Best case: Powered flight. Transistor circuitry. V2 rocket.
Basically 1940s tech, minus the atomic bomb and jet engine.
The most important assumption I've made for this; is they have all of humanities knowledge as of 2020, not just "western white-guy" knowledge. 18th and 19th century European explorers would die in the hostile jungle, right next to local tribes who'd been living entirely in the jungle for generations. All the other answers about "everyone will die in a few weeks" is forgetting about the knowledge of traditional peoples.
If we approach this using the knowledge of western white guys - yeah we'll all die.
If we approach this using all the knowledge of the human race, we'll catch up to about 1820's standards of living in about 20 years.
What do we start with?
For a million people looking at nothing but empty land the "Giant leap for mankind" moment looks a long way away, but, like I answered on your previous question, the single minded organisation allows us to imply group consent, which shows this is all pre planned in advanced. Because of that preplanning:
- They've landed based on the availability on resources. While a full geological survey probably hasn't been done they know how many people can live in a given region without requiring industrial farming, and have probably distributed around a nice warm continent in such a way that minimal shelter is needed, water is available, and food can be gathered in sufficient quantities year round easily while farms are being set up.
- They have the clothes on their backs and shoes on their feet, nothing else.
- They don't know exactly where minerals are, but they have a good idea from the planning stages about where to look for what based on current geological knowledge, and scatter people near those places too.
- They've preplanned all tasks that need to happen. They've sorted the tech tree and can work on multiple things in parallel.
- They can choose to invest resources in advancement, rather than comfort. They know how to make a TV, but rather than putting resources into mass producing them, instead focused on getting to the next tech level rather than making themselves more comfortable.
- They can optimise their society in a way which prioritises achieving the next milestone over comfort. When there's idle capacity in the workforce comforts can be made, but people should be prioritising building the next achievement over their own quality of life.
Tasks are much faster the second time around
As an example; Edison (and his lab) tried over 3000 variations of the light bulb. Your guys don't need to do that. They have 2020 knowledge allowing them to just choose the right one. So once power and glass blowing and tungsten are available, you can have the incandescent light bulb within days, not years.
Same with the AC motor it took Tesla and Westinghouse 4 years to develop a working AC motor. With 2020 knowledge, once power, copper wires and magnets is available, your guys can build this in a few days, not years.
It was 22 years between the patenting of a transistor in 1926 and a functional device being released in 1948. Much experimentation was done (especially with a war driving demand for radios and such), but it wasn't until Bell labs in 1947 tried an experiment with gold and silicon that we got the first transistors. Your guys can skip those 22 years and as soon as decent silicon is available they can get a prototype transistor.
They know how to refine minerals, and as soon as a forge can be built (needing bellows and clay bricks), can get it right first time. They know how to extrude copper into wire, they know how to make silicon from hot quartz sand, and they know the applications of that in advance. Steel took considerable experimentation to achieve, getting the ratios of carbon to iron right via controlling the carbon dioxide production is non trivial, but your guys know how to build a steel forge as soon as iron, coal, bellows, and bricks are available.
Same with powered flight, tyres, indoor plumbing, textile manufacturing, basically every advance humanity has made had a period of experimentation before it, which you can skip or greatly reduce because you know the answers.
You can fly through the stone age (only needing it for simple mining and tree felling) and will probably have copper or bronze tools partially available before everyone has a house built (climate is real nice, remember). Actually come to think of it why bother having one house per family? They're single minded and devoted to the task - make it one house per group of 20, put them in bunks or even cuddled up together and get some economies of scale with meal prep and child raising.
There are also many advantages 2020 knowledge gives even when absent of stuff. You know first aid, how to lift heavy loads without hurting yourself, sanitation, quarantining sick, you understand project management, engineering, and botany. You understand how to build a mine safely, how to forecast the weather 24 hours out from local observations, how to navigate based on celestial body positions. You know natural medicines and bush tucker. You know wilderness survival tricks.
You know what technologies work out in the end (e.g. windmills) and what doesn't (Alchemy). Your society will fly through the tech tree because it's done it before and knows the way.
A 10 year old girl who landed in the original settlement, dying of old age at 85 in a hospital bed, will see her grandchildren launch a V2 style rocket that leaves the atmosphere. Her child, dying of old age 20 years later, will probably see the moon landing from her hospital bed.
Rough timeline:
Week 1-2
- Travel to prearranged positions around land.
- The land is very fertile (it was chosen this way), and your people know how to find food and water in the wild in transit.
- They travel in large groups, predators are few (remember land was chosen in advance) and those that do exist here are unlikely to attack a large group.
Week 2-5
- 50% go out hunter / gathering.
- Optimistically, you only need 1 food maker per 3 - 5 people, (or done as per Aboriginal hunting parties of 5, gathering parties of 5, feeding a family of 30). but working on a 1:2 ratio adds a level of safety and to make up for the non-evolution of plants which humanity didn't selectively breed.
- 45% building tools
- stone axes for land clearing
- stone picks for mining
- hoes for land turning
- better hunting tools.
- simple woven baskets to aid in food gathering
- 5% exploring pre-identified possible ore deposits.
- focusing on potential clay, coal, iron, or copper.
Month 2-3:
- 50% go out hunter / gathering.
- 20% exploring pre-identified possible ore deposits.
- 5% mining clay and copper/iron
- 15% cutting down trees, for wood and clearing for farmland.
- 10% build simple huts - shelter from storms now, but mostly for food storage.
Month 4-5:
- 50% go out hunter / gathering.
- 10% exploring pre-identified possible ore deposits.
- 5% making clay pottery:
- bricks for better forges
- pottery for food & water storage,
- 5% mining clay and iron/copper
- 5% preparing farmland.
- 10% making simple shelters
- 5% digging kilns into hillsides for simple processing.
Month 6-7:
- 50% go out hunter / gathering.
- 20% preparing farmland.
- 5% mining copper/iron
- 5% making copper/iron tools
- 10% making shelters.
- 10% making replacement clothing.
Month 8-12:
- 50% go out hunter / gathering.
- 30% working farmland.
- 5% mining copper/iron
- 5% making copper/iron tools
- 10% trading with neighbouring colonies - resources in starting colonies are unlikely to be evenly distributed.
Year 2:
- 30% go out hunter / gathering.
- 40% working farmland.
- 10% mining simple resources (copper / coal / iron / sand etc)
- 5% making better tools
- 5% setting up simple refining infrastructure (brick and fire forges), and starting to refine copper, iron, quartz, glass, and other simple things.
- 10% trading with neighbouring colonies
Year 3-8:
- 20% go out hunter / gathering.
- 50% working farmland.
- 10% mining simple resources (copper / coal / iron / sand etc)
- 5% refining simple resources (pure copper, pure iron, glass)
- 5% improving existing tools using refinements
- 5% transporting goods between colonies to make up for local shortages.
- 5% replacing worn clothing, shoes, tools, etc.
- Make Gunpowder (or another similar early explosive), use it to mine faster.
Year 9-13:
- 10% go out hunter / gathering.
- 40% working farmland.
- 15% mining and refining resources
- Join adjacent colonies together into small towns, keeping any productive farms only as farming communities feeding food into the towns.
- Start making mediocre steel (Iron and coal), silicon (Quartz sand), and other similar technologies.
- First magnets, copper wire, and pumps.
- First steam engine.
- otherwise approximate technical parity with the 1810s.
Year 13-20:
- 45% making food from farmland / hunter / gathering.
- 15% mining and refining resources
- First power generation (ideally hydroelectric, but can be coal or wind depending on locale)
- First batteries
- 5% of people involved in trading between 50 towns of ~20,000 people.
- Otherwise Basic technical parity with the 1820s.
Year 21-25:
- Basic electrical parts. Relays and diodes.
- Use power to create aluminium, and other similarly refined things.
- Start casting alumiumium and steel in bulk.
- Basic technical parity with the 1830s.
Year 21-25:
- Spanners, wrenches, and other modern manual tools.
- Sewing machines.
- Vulcanised rubber.
- Long distance telegraph lines.
- Basic technical parity with the 1840s.
Year 26-30:
- Refrigeration
- Railways with steel tracks between towns.
- Basic technical parity with the 1850s.
Year 31-35:
- Telephone connection point-to-point.
- Photography
- Basic technical parity with the 1860s.
Year 36-40:
- AC power generation
- Hydralic / phumatic hand tools
- Basic technical parity with the 1870s.
Year 41-45:
- Two stroke engine
- Telephone exchange.
- Basic technical parity with the 1880s.
Year 46-50:
- Punch card machines
- First Electric car
- First radio
- Basic technical parity with the 1890s.
Year 51-55:
- Vacuum cleaners
- razors
- powered flight
- Basic technical parity with the 1900s.
Year 56-60:
- Power in households
- Electrolysis
- Basic technical parity with the 1910s.
Year 61-65:
- Video transmision.
- Simple rocketry
- Basic technical parity with the 1920s.
Year 66-70:
- Ballpoint pen.
- Cryogenic temperatures
- Basic technical parity with the 1930s.
Year 71-75:
- Transistor.
- Rocket leaving the atmosphere (not orbit)
- Basic technical parity with the 1940s.