Digipuzzle is a great site for finding a wide range of free online games, activities, and puzzles. This is a great way to introduce Game Based Learning into the classroom as well as for computer "centers". Also, there is a section titled "USA" which is a nice section for finding educational games/activities for on USA history/states/capitals, etc.
I highly recommend checking out Digipuzzle by clicking here!!!
*Digipuzzle is an advertiser of Technology Tidbits.