A sequel to Could a Time Traveller Prevent the Black Plague?

Todd the time traveler's a cool dude and has decided to use his powers for good, more specifically he wants to stop the American Civil War from happening. His powers work in a similar fashion to the time travelers from the Butterfly Effect movies; the time traveler is immune to paradoxes, he remembers everything about the alternate histories. The key difference being

  1. He can only go back in time to one year once (for example, if he goes back to 1812, he can never go there again) and goes back to his time after that year is over;
  2. He can only go back in time by reading (or looking at) information of the past; Pictures, newspapers, historical texts, etc.

Some details about Todd

  • He served as a medic for the Turkish Land Forces for 16 years and is very skilled in medicine.
  • Other than his military service and experience, he is an average White male.

Using his modern medical knowledge would Todd have a chance at stopping the American Civil War from happening?

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    $\begingroup$ Whatever happened in the past includes all the effects of any time travelers. There is nothing to change, if you end up traveling back in time to do something, then whatever happened in the past already includes what you'll end up doing. Any paradoxes about this involve a notion of free will allowing you to deliberately do something else than what actually occurred in the past, but the resolution of this paradox in a universe that allows for time travel involves accepting that humans are just machines subject to the laws of physics, there is no such thing as free will. $\endgroup$ – Count Iblis Jun 22 '16 at 19:29
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    $\begingroup$ @CountIblis I very clearly said that paradoxes are ignored here. $\endgroup$ – TrEs-2b Jun 22 '16 at 19:30
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    $\begingroup$ Given that it was the Civil War that ultimately put an end to slavery in the US, I'm not sure that preventing it would actually be using his powers for good. $\endgroup$ – celtschk Jun 22 '16 at 20:19
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    $\begingroup$ @celtschk The Civil War was fought because the north and south disagreed over slavery. If slavery wasn't a part of the culture to begin with, then that conflict would have been avoided. All he has to do is go back and counter social Darwinism before it leads to widespread slavery. $\endgroup$ – Frostfyre Jun 23 '16 at 12:04
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    $\begingroup$ @Azor-Ahai Maybe he goes back for a 12 month period, and afterward he can never go back anywhere inside those 12 months again. $\endgroup$ – AndyD273 Jun 23 '16 at 17:44

11 Answers 11


I know that the civil war was not solely about slavery, but it was definitely one of the major factors.

To defuse that part of the conflict he should go back to the very founding of the nation.
Thomas Jefferson tried to get an anti-slavery clause in the Declaration of Independence, and I remember from history that the subject was raised so many times that some other members of congress basically made a ban on the subject.

So armed with a large war chest (or at least a way to make a lot of money, possibly through trips to earlier times to lay the groundwork) and plans for a few industrial revolution technologies, Todd should wage an enormous social, political, and economic lobbying campaign to turn the population against slavery, convince the continental congress that slavery is wrong, and convince the business men of the time that importing slaves would be going against their long term interest.

By removing slavery from the root, the rest of the plant avoids the poison.

On an ironic note, by stopping the importing of slaves, we are keeping them out of our history, meaning that all of the progress, discoveries, and contributions that their descendants made to our country would not have happened.
Some of those Africans may have immigrated to a free USA on their own, but not in the same numbers or in the same way, and so those descendants would not have happened.
Also, most of those enslaved were enslaved by other African tribes as a result of war, and if they couldn't be captured and sold to the slavers they may have been killed instead.

Also, peanut butter may not have been discovered.

EDIT: I guess peanut butter would have been discovered, but George Washington Carver did invent over 300 other uses and made the peanut popular.

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    $\begingroup$ Interesting, although I personally think it would be hard to say that some of those things wouldn't have been invented/discovered by other people. Did it have to be a slave (or ex-slave, or descendant of a slave) that did it, or did they just happen to be in the right place at the right time, which could have happened to someone else? $\endgroup$ – lsd Sep 27 '16 at 14:36
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    $\begingroup$ Enslavement in Africa were fuelled by demand out of Africa, therefore outlawing slavery in the USA would have got less African people enslaved and transported. Anyway, importation of slaves was banned in the USA in 1807, so outlawing in 1776 would just have avoided a couple decades of transatlantic trade. Furthermore it could have made the Southern colonies to side with the British side in the American Revolution - probably making the Revolution to stall. $\endgroup$ – Pere Feb 1 '17 at 13:09
  • $\begingroup$ @Pere Good info about the import ban. I'm not suggesting they outlaw importing slaves in 1776, but slavery entirely. In 1776 it wasn't a North South issue, as there were as many slaves in the North as in the South. That's why Thomas Jefferson became somewhat unpopular on the issue because he was one of the few in congress trying to abolish it. A big reason the South wanted slaves in the CW was because their economy was dependent on cheap labor. If that dependence could have been rooted out early then it would have been much easier. By 1861 it was in to deep. $\endgroup$ – AndyD273 Feb 1 '17 at 14:44
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    $\begingroup$ George Washington Carver didn't invent peanut butter. $\endgroup$ – Mike Nichols Jan 29 '18 at 17:35
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    $\begingroup$ @KeithMorrison I was mostly working to avoid sweeping generalizations, and because the war had two sides. The south went to war and wanted to leave the union because of slavery. The north went to war to keep the south from leaving. President Lincoln was against slavery, but felt that keeping the union together was more important than freeing the slaves. My main agrees with you that none of the other complaints would have been remotely important enough to start a war over. $\endgroup$ – AndyD273 Jan 29 '18 at 18:51

It would be easier for Todd to end the war early for one side or the other. He could also delay the start of the war. However it is unlikely that with only one trip he would be able to entirely stop the civil war. The underlying issues dividing the country ran to deep and had already led to bloodshed between the North and the South.

Todd could stop the formation of the republican party, or even rig the elections so Abraham Lincoln lost the election. But some other abolitionist party would form, and a different abolitionist president would be elected, and the south would leave the union.

The best hope for peaceful resolution would be to guide the formation of an abolitionist party, and get an abolitionist president (perhaps himself) elected who would let the southern states cede away without starting any northern lead conflict. This might even halt the cession of states at the initial 7. Perhaps a later Mexican/Confederate war with Mexican success might lead to several of the states rejoining the Union. But other political events might also lead more states to leave the Union. Too much is up in the air.

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    $\begingroup$ You should read Harry Turtledove's Southern Victory series en.wikipedia.org/wiki/Harry_Turtledove#Southern_Victory $\endgroup$ – Marshall Tigerus Jun 22 '16 at 19:30
  • $\begingroup$ I have. That is again ending the war early, not avoiding it. $\endgroup$ – PCSgtL Jun 22 '16 at 19:43
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    $\begingroup$ I wasn't mentioning it as an answer to the question, just thought you might enjoy it with your thought process :) $\endgroup$ – Marshall Tigerus Jun 22 '16 at 19:43

He could stop Eli Whitney from inventing the cotton gin. 60% of slaves worked on cotton plantations, and 2/3 of U.S. exports were cotton, so no short staple cotton, no cotton belt. Though he might have to keep going back to stop the "next" discovery of the cotton gin. :)


My vote is going to be Yes, but with a big old asterisk.

He could not prevent the war from happening, as the civil war had a lot of causes that I'm not going to go into here (there are numerous documentaries and resources if you are really interested in it). It is highly unlikely that he could resolve all of those problems in such a way that some subset of states would not rebel in a civil war at some time, it is really just a matter of when and how severe it was.

However, he could change the nature of the war so that it was no longer considered a civil war. Perhaps he prevents the United States from being formed, and allows the states to exist more like Europe, as a collection of separate nations that sometimes cooperate. In this case, it would be a war between countries, not a civil war.

He could also prevent the New World from being discovered for some time, where the later colonization of the New World would result in a massively different landscape where the Civil War could not occur.

Using his medical knowledge, he could create the conditions for a terrible plague to sweep through the United States many years prior to the Civil War, which would reduce manpower to the point that a Civil War is not a prospect either the North or South could stomach or effectively fight.

He could also generate some sort of "Pearl Harbor" effect, where the US is incited to violence against a common enemy.

He could also go back to the first humans, murder them all, and prevent the Human Race from ever evolving.

In all of those ways, he is not actually solving the problem of the Civil War or making the world better, per say, but he is technically stopping the Civil War.

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    $\begingroup$ Or he could prevent the genocide of the native Americans from happening. $\endgroup$ – Martin Schröder Jun 23 '16 at 5:58

You look at how other countries solved the slave problem. Britain for example, eliminated slavery in the empire by paying restitution for slaves in the Slave Abolition act of 1833. The cost of this amounted to about 5% of their annual GDP.

The immediate financial cost alone of the US Civil war exceeded 200% of the annual GDP, it also kill about 4% of the male population, injured far more and burdened the country with decades of large costs for reconstruction, veteran's benefits, etc.

By carrying back convincing evidence of the ultimate costs of slavery, to the time of the countries foundation, it would have been possible to convince others that slavery must must be abolished and that all men must be free. The country could have raised the funds to compensate the existing slave-owners, even though it would have been difficult, the government could have sold assets, sold bonds, etc. to make it happen.

Clearly, this has little to do with the traveler's medical knowledge, but this is not really unexpected. Preventing a war requires a political change, not new medical techniques. In fact, improved medical knowledge knowledge has the opposite effect, since keeping soldiers alive reduces the cost of waging war.


Yes, he could...or if not, would radically change the nature of the conflict

The general consensus is the US Civil War started over whether the federal government had the authority to dictate whether slavery would be permitted in the western territories or not. The North said it did. The South said it didn't.

Interesting to note that the slavery question was discussed extensively in the 1770s and 1780s when the Constitution and Bill of Rights were written. During this discussion, the Founding Fathers punted the question and compromised.

Pay Them or Die

Suppose our time traveler went back to the decisive discussion where the compromise was made and the stage set for bloody conflict in the 1860s. Behind these closed doors, he would be able to make the case for the elimination of slavery in a kind of Do or Die scenario. The Southern delegates in the meeting have a choice: gracefully acquiesce the slave system in the South now (1780s or 1790s) or have it forcibly destroyed in the 1860s. (Probably don't give dates since if the delegates don't agree, they will go home and use your information to arm the South).

Make as many economic and political arguments as required. Remember that the delegates to these meetings are incredibly intelligent men so the arguments must be solid. Making modern moral arguments likely won't work since many Southerners didn't consider slaves (or blacks in general) to be human and thereof undeserving of humane treatment or autonomy of any kind. (Reading up on their justifications are absolutely appalling to modern readers, generally.)

"To the Southern Gentlemen of the Conference,

The case is put to you that slavery must and will end in these United States. Whether this is by bloody conflict or peaceful resolution, it is for them to decide. If they choose to retain their slaves then know that they retain them at the cost of the best blood of their children or children's children. Are they willing to pay in the hundreds of thousands of dead on both sides? Will they pay in the utter destruction of their greatest cities and the starvation of tens of thousands who ordinarily live in plenty? Will they countenance the absolute destruction of their way of life that they claim to hold so dear?"


Slaveruy has been a part pf human society for as far back as we can examine records, so the actions of the abolitionists in both England and the Northern States in the 1700's was almost without precedent. If you are looking for contrafactuals, it might be easier to postulate that slavery was never abolished at all, and continues to this day (as it still does in places like Sudan).

The place to stop slavery must be before the founding of the United States, so your hero might have to go back in time to the 1600's in order to ensure that future slave owners are not given the chance to come to the Americas, discover a way to ensure that economic activities which do not involve slave owning can prevail over those which require slave owning (so trade in sugar, tobacco and cotton will need to be somehow suppressed), or at the extreme range, sit offshore and sink any and all slaveships which make it across the Atlantic.

Extreme measures will be needed since the advantages of Chattel slavery in the pre mechanized age generally outweigh the disadvantages (as ancient societies from Egypt on can attest). Economic gain is a powerful motivator, so whatever advantages that can be gained will be sought after, hoarded and social and political structures developed to quantify and preserve these advantages. It is the attempted preservation of these advantages which caused the divergence of the North and South, and created the political strains which eventually led to the Civil War in the first place.

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    $\begingroup$ This is very wrong. Slavery was abolished in Lithuania in 1588. Japan banned in it 1590 (except as punishment for criminals). Russia abolished slavery in 1723 (but kept serfdom). Portugal banned the importation of slaves in 1761, and abolition began in 1773. France abolished slavery in all its territories in 1793 (Napolean, the prick, brought it back for sugar-cane colonies). And so on. $\endgroup$ – Keith Morrison Jan 29 '18 at 5:04
  • $\begingroup$ True but irrelevant. The issue is American colonists establishing a society and economy using chattel slavery as the driving factor, rather than some other economic system which did not depend on slavery. $\endgroup$ – Thucydides Jan 29 '18 at 21:20

If the time traveler was willing to kill or enslave hundreds or thousands of persons to prevent the horrors of slavery and the deaths of hundreds of thousands in the Civil War, he could go back to colonial times to prevent the adoption of slavery in the colonies.

Many stories of early America imply that the Pilgrims at Plymouth were the founders of the colonies, even though the Jamestown setters were the very first, a distortion partially caused by dislike of slavery.

So he could go back in time to 1608 Jamestown and wipe out the colony there. But that disaster might prevent the 1620 settlement of Plymouth. So maybe he should wait until after the 1620 settlement of Plymouth and then wipe out the Virginia colony.

Fortunately the Virginia colony was still small in the 1620s. in 1622, just two years after the Plymouth settlement, the Powhatan Confederation launched a surprise attack on the Virginia settlements, killing three or four hundred men, women, and children, about a quarter to a third of the entire colony.

The Powhatans then waited for the English to surrender or to sail back to England. But the settlers instead fought back in a war that lasted for years.

So the time traveler could find a way to make the Powhatan attack stronger.

He could go to Spain, hire some ships, and hire some Spanish mercenaries to attack the English in Virginia at the same time that Powhatans attacked. Since the Spanish government claimed all of North America and considered all English settlers criminals, the Spanish government might not frown on the expedition.

Maybe he could also organize a French and/or Barbary pirate attack on the Jamestown colony. There is nothing like multiple attacks at the same time to make the survivors abandon their colony.

He could go to the Powhatan leaders and urge them to make a stronger attack and to keep it up after the first day. He could advise them to make an alliance with the mighty Iroquois in the north. They could agree to become subordinates to the Iroquois in return for being reinforced by hundreds of Iroquois warriors to make the surprise attack even more devastating. And maybe he could persuade or bribe the Dutch traders at Albany to send one or more ships armed with cannon to smash the palisade at Jamestown and capture it, leaving the English colonists without a secure fortress during the Powhatan attack.

He could provide the Powhatans with many guns and much ammunition.

Thus he might wipe out the Virginia colony and prevent it from developing a slave based economy while keeping the Plymouth colony.

And he would probably have to repeat that over and over again when new colonies in the southern USA are attempted. He should give the southern Indian tribes vaccinations against old world diseases and other medical care - thus saving many thousands of lives even if his plan fails - so they will have more warriors, arm them with guns and ammunition, and whenever a new southern colony was attempted bribe with trade goods a wide coalition of tribes to attack and destroy the colony before it could develop a slave based economy.

Thus he might delay for generations or centuries the settlement of the South and the development of a slavery based economy there, and make the southern population much smaller during the 1860s if there is one at all, and make it easier for slavery to be as peacefully abolished in the entire USA as it was in the northern states.


It might be an interesting challenge, but a curious experiment... but even at the time, the south insisted the north didn't care about slavery, they were just using it to galvanize their people into action.

Assuming slavery WASN'T as important as independence/taxes/commerce as they claimed there is a move they didn't pursue.

The south could pre-emptively abolish slavery... sorta. They could replace it (as is the way of our species) with something that was nearly the same thing (a company store creating debt slavery, for instance). Their "property" becomes "free" but has little choice but to continue to work for basically nothing, while knocking the arguments of the north out from under them.

It would be a lot harder to rally people to fight and die for interstate commerce regulation.

Of course, it does NOTHING to correct the moral issues related to the conflict... in fact, it probably puts in place structures that would take much much longer to deconstruct... but it could stop the war itself.

Todd... if he could use his skills to become important and valuable enough to the confederacy, he could eventually get the ears of those who could hear the logic and be led to make those decisions.


I'm going to go with "no" for one reason, and that's the argument made in Quantum Break. You can't change the past, and by trying, you will only cause the event you are trying to change. This is an example given in the game: Say you have an egg sitting on a table. You step out of the room for one second, and when you get back, the egg is broken. Say that egg was really important to you, so you go back in time, rush into the room after the past you leaves, and you bump into the table, knocking the egg down and breaking it. You caused the very thing you were trying to prevent.

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    $\begingroup$ That's one possible view of time travel - but by no means the only view of time travel. You could just as easily assume a butterfly effect, where the mere act of going back changes air currents which changes [insert a whole long slew of coincidences here] which changes the event. Until someone actually develops time travel (if that's even possible), this is mere speculation. $\endgroup$ – Ghotir Jun 23 '16 at 16:22
  • $\begingroup$ @Ghotir: My understanding is the equivalent of "you can't change the past you have observed" is proven in General Relativity even given active time travel but the question assumes the opposite. The related proof is not available in Quantum SR (Quantum GR is not available). $\endgroup$ – Joshua Jan 28 '18 at 19:21
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    $\begingroup$ My degree is in general relativity... but it's been longer than I care to admit since I've done any work or study in the field. I am firmly of the opinion, however, that until we actually have some sort of testable hypothesis of time travel... "anything goes" is the best answer to a prospective author. Just be internally consistent! $\endgroup$ – Ghotir Jan 29 '18 at 16:27

There's a tremendously high chance that he can change the existence of the American Civil War, by acting in countless ways as some fine examples of choices already given.

Another example if you would like to capitalize on the medical background of the character would be to hasten communication at the time that citrus fruits and teas of certain pine needles will cure scurvy. This disease of vitamin c deficiency was still rampant at the time and the cure was only just becoming known. Scurvy certainly caused the death or retarding of progress to another set of VIP characters from across the sea that had developed... (can branch out here to as many plot twists as you can imagine)...a massive plan to infiltrate the colonial government in order to achieve their political goal of (pick one). Alas, their ship's crew had not yet learned the secret of the other big "C" and had all succumbed to scurvy. While the upper class conspirators were fine with their sweet dried fruits tiding them over, not a one had a clue how to navigate the ocean. They ended up in the Bahamas and fell in love with the place and stayed there.

Actually, I don't know if that's what happened to them for sure, since they are made up and this is your story, but hopefully helps you realize how easily events can be changed by a single detail like sharing your fruit with your boatmates. If only your time traveler had showed up during loading of the boat to add crates of dried fruits for those sailors.


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