This handy guide will help you determine whether your ancestor served in the U.S. Army State Volunteers in the War of 1812 by using the Compiled Military Service Records (CMSRs). For U.S. Regular Army veterans, learn how to use enlistment, discharge, and prisoner of war records. For those who served in the U.S. Navy and U.S. Marine Corps, using muster and pay rolls, casualty reports, and courts martial records may allow you to further your research.