I never had a hard time finding Revolutionary War ancestors in my family tree. Most of my family was from York, Chester and Lancaster Counties in South Carolina, an area where many battles were fought (Cowpens, Kings Mountain, Musgrove’s Mill, Waxhaws, Huck’s Defeat, Fishing Creek). But not everyone has it that easy. A great resource is Revolutionary War Pension applications. Testimonials were written by the Patriots or their widows and witnesses so that the individual or survivors could get a pension from the US government. One of my favorite books on a Revolutionary War battle, The Day it Rained Militia, is almost completely based on pension application testimonials from Patriots who fought at the Battle of Huck’s Defeat.
Over at Eastman’s Online there is a detailed post about finding your Revolutionary War ancestors.