They don't. There aren't any passenger lines between the two countries.
From the US? It is international travel. If you mean NEW Mexico, that is domestic travel, though.
No.
Travel was not restricted into Mexico, so many people continued to travel in and out of the country. Many international airports were screening people for symptoms as they entered the countries from Mexico and the US and, in some cases, they were retained without entry until medically examined to determine if ill with flu-like illness, but that was only done in some countries. At one point early in the epidemic in North America the US State Dept. recommended to US citizens that travel to Mexico be restricted to "essential only." At that time most people reduced travel into Mexico but "essential" travel was still happening. Many vacationers did reschedule their trips into Mexico, but some continued to go to locations outside the larger cities (and especially avoided areas near Mexico City where the epidemic was rapidly spreading and where the new virus was first discovered.)
New York
by a train or us army jet
we can't travel across the sea by train...
Yes.
If in Mexico travel north. There is a border crossing. Pass that and you are in the US
In the United States, approximately 31 million people travel by train each year, primarily using Amtrak services for intercity travel. This number can fluctuate based on factors such as economic conditions and travel trends. Additionally, commuter rail services in major metropolitan areas add millions more riders to the overall total. Overall, train travel represents a smaller portion of the total transportation market compared to cars and planes.
As long as you have an American passport, you can enter Mexico. Problem is on your way back to the US. Without a valid proof of citizenship, you will not be abe to return to US soil.
Yes, provided you have an American passport.
Yes, they do.