My setting is in the near-future, approximately 200 years from now. Among the many technological advances that have come about are ultra highspeed trains. For the purposes of this question, traveling on these trains works much like a subway, they have high throughput and relatively low wait times when compared to airports.
Even now, projects like Elon Musk's Hyperloop and projects in China are attempting to reach speeds from 700 to 1800 miles per hour. But consider what would happen if trains existed that could reach speeds in the multiple thousands of mph, say 4,000 mph for example.
The USA is only 2,860 miles at its widest. Even considering the time it would take to board and disembark, one could conceivably travel from the east to the west coast in as little as an hour.
What sort of effects would we see in society? How would laws, global politics, and peoples' daily lives change when one could cross the US (or whatever continent of choice) in 1-5 hours?