I had somebody tell me that it didn't count for being in a state if you hadn't spent the night there - like if you just drove through it 'didn't count'...
With that said, my list is:
Florida, Georgia, North Carolina, South Carolina, Virginia, West Virginia, Wash. DC, Maryland, New York, Pennsylvania, New Jersey, Ohio, Michigan, Indiana, Kentucky, Tennessee, Alabama, Mississippi, Louisiana, Texas, Arkansas, Missouri, Kansas, Minnesota, Wisconsin, Illinois... and Oklahoma - LOL - we stopped the car and walked around just so we could say we'd been there ....