Can one really just travel across the country on foot or by train?

I mean I've never tried, but I would love to. Any guides, tips, etc.? Hoping to take minimum things with me.

 

Damn that's good!

 

by train i imagine no problems---I hitched from SAn diego to Norfolk VA many ,many yrs ago---i would think that might be a bit more difficult these days

It was a great experience---way too many stories to put here....

 

Yes, it is. There's no reason why it isn't physically possible to walk across the country.
Practically, it would take a lot though. You would need to be able to obtain food+water, shelter sometimes, and be able to protect yourself. I'm sure there's plenty more you would need, but that's just some basics.
Since you didn't state which country, I'm assuming you mean the USA. This would apply to other countries just as well though.
If you're interested in actually doing this, I'd suggest it. I'd love to do something similar myself one day.
Just keep in mind that it would probably be a hell of a lot different than the life you live now. Walking across the country takes some time, you'd be gone for a while, so be prepared to live life differently.
Wherever you go, it's likely that you could find someone who would be willing to trade shelter and sustenance in exchange for work.
If you can, i'd try to be sure you have money just in case(preferably mostly in the bank id assume, so you don't get it stolen or lost), but that's not to say that it isn't possible to leave your home with nothing, and make your way across the country. I just wouldn't recommend it if you can avoid it.
If you don't already, get to know some things about camping and survival. That would help a lot in areas where there aren't too many places to stay, or do exchange labor.
That's all I can think of for now, but I'll contribute more if i think of it.
Have any questions in particular?
I hope i can learn some things myself in this thread since i'd love to do the same someday