Gettysburg Gamers offer a set of quick and free wargames rules for the French and Indian War and American Revolution.
Richard Bradley of the Tyneside Wargames Club offers a set of free wargames rules for skirmishes in the French and Indian War. The rules have a nice touch with the use of NCOs in command.
D3 French and Indian War is a set of free wargames rules designed for play on a 6 inch square grid.
Rex Hurley has written a set of free wargames rules for playing Last of the Mohicans with 25mm – 28mm wargames miniatures. The rules are relatively simple, and include statistics for all of the main characters, such as Hawkeye, Uncas, Chingachgook, Magua, et. al.
There’s also a page of pictures for inspiration.
This Yahoo group has free wargames rules for recreating battles of the Indian Wars in the Old Northwest: the French and Indian War through the Blackhawk War.