More research options:
If you are looking for pre-20th century information....
(1) Local histories [state, county, etc.] often give the military history of the area. Regiments and individuals may be mentioned, as well as bios of soldiers.
(2) Biographical records of cities, counties, etc. will detail the lives of prominent citizens. Military service is generally included, as well as service of ancestors.
(3) Civil War Soldiers and Sailors database: searchable for Union and Confederate servicemen. Database will give you unit, state, regiment of soldier/sailor. There are also collections of stories, photographs and the like.
(4) Valley Forge Legacy: The Muster Roll Project: Allows you to search for Rev War soldiers who were at the Valley Forge encampment. Below is the entry for my Edward Prall [you may have to be spelling specific]. The list of dates are from muster rolls. Some entries may give more details. This includes companies or regiments that were on coastal guard duty to protect the army from British invasion. http://valleyforgemusterroll.org/muster.asp
|ID||Last Name||First Name||Rank||State||Regiment|