I need your advice about travel in the U.S.

Hi everybody! My son, 18 yrs old, will be in the States soon. His sister in Texas is going to help him do the GED. Then around the 1st of July, he's probably going to go north to Minnesota where he will work for the rest of the summer.

He'll be traveling with a suitcase, an new amplifier (hopefully not too big), 1 acoustic guitar, and 1 electric Gibson.

He doesn't know the States except for 1 visit when he was 15, and that was just 1 month for Christmas at his grand mother's.

He won't have a driver's license yet. Long ago when I was a student in the U.S. I sometimes I took Greyhound. Is that still a good way to get around, my daughter seems to think it is not safe? When you have layovers and need to change buses is your luggage checked through to your destination? If he's going to take a plane everytime he needs to go somewhere, the travel costs add up pretty fast.

Your advice is welcome! Here in Europe, the trains and buses are great, and safe, but it sounds like air travel is the only alternative in the U.S. according to my daughter. But she's only been living there for 2 years, so maybe she's just going by impressions.

Thanks in advance.
Mike