Loose Files and American Scramble by Andy Callan was one of the first American Revolution games that I played. Originally published in Wargames Illustrated in 1987, it is a lot of fun.
Rules: 18th Century
Free Black Powder, Hail Caesar and Pike & Shotte Rules
For a limited time, Warlord Games is offering free digital copies of Black Powder, Hail Caesar and Pike & Shotte
American War of Independence Wargames Rules
American War of Independence is a set of free wargames rules based on Neil Thomas’ Napoleonic Wargaming and Ancient and Medieval Wargaming. Interestingly, all movement is based on “base widths.”
6+ Rules – 6mm Rules For Horse and Musket
6+ Rules are a set of rules for the horse and musket period in 6mm. It uses no dice
Warhammer French and Indian War
Warhammer French and Indian War is a set of free wargames rules based on the Warhammer English Civil War rules.