The rough overly simple version is that the initial hotspots (New York area especially) were hit really badly, then did a good job of squashing the bug. Some re-opened too early and in stupid ways, and saw their cases go up again, while in MAGAland the rebellion against LOCKDOWN TYRANNY created new hotspots.
The first trough (first part of this graph) was not good enough, and not as good (adjusted for population) as the troughs European countries managed after their first big waves, but it was a success of sorts. Then the second wave, followed by a new effort even in MAGAland, and eventually cases started to fall again, but then more reopening and schools and universities and...
(source)
It's never going to end and your passport is useless.