Could you do a U.S. East Coast transit trip?

I’ve been watching YouTuber Adam Does Not Exist and his transit trip from San Francisco to Seattle (https://youtu.be/7OQwA95sMbg). He previously did San Francisco to Los Angeles via transit.

I know a few folks have gone from the Canadian border to the Mexican border on transit on the West Coast.

And Miles in Transit has done D.C. to Boston via transit (https://youtu.be/0lNyPlQWRAg).

How close could you get to doing the entire East Coast on transit? Let’s say Calais, Maine, to Key West.

My guess is you could get to Petersburg, Virginia, somewhat easily, but it’d get dicey after that. And then Jacksonville to Key West would be doable, I think.

Let’s say for the purposes of the challenge, you can go as much inland as you need. So if going through Atlanta and/or Charlotte helps, fine.

And the usual rules, no Amtrak or intercity buses like Greyhound. Very infrequent transit buses are fine.