Total of 35 so far. In approximate chronological order, they are:
Birth – 5 Years Old:
Texas, Oklahoma, California
12 Years Old:
Arizona, New Mexico, Louisiana, Arkansas, Tennessee
13 Years Old:
Kentucky, West Virginia, Maryland, Pennsylvania, New York, Vermont, New Hampshire, Maine, Massachusetts, Rhode Island, Connecticut, New Jersey, Delaware, Virginia
14 Years Old:
Indiana, Illinois
15 Years Old:
Wisconsin
17 Years Old:
Minnesota, Missouri
20 Years Old:
Washington (State)
22 Years Old:
Mississippi, Alabama, Florida
23 Years Old:
Georgia, South Carolina, North Carolina
27 Years Old:
Colorado
As you can see, I saw a lot of the U.S. when I was younger, because my stepfather was in the Army and we moved frequently. Also, my grandparents took me on one of their bus trips when I was 13 years old, so I saw the northeastern U.S. for the first time then. I apparently haven’t been in a new state for over a decade, now, though!
I have been in an airport in Michigan and possibly Ohio, but didn’t count them.
P.S. Interestingly, I’ve never set foot in the state of Alaska, but I did spend a month or so on the pack ice 50-100 miles north of Alaska, which not many people can say.