Irvin McDowell was a prominent figure during the early months of the Civil War. With so much at stake, he was called upon to lead the Union’s largest Eastern Theater army. Pressed by the media and President Abraham Lincoln to move into Virginia and defeat the Confederates gathering there, McDowell led his neophyte army out to the plains of Manassas and was soundly defeated. McDowell went on to hold an independent command in northern Virginia during the Peninsula Campaign and serve in the Army of Virginia under Maj. Gen. John Pope during the disastrous Second Bull Run Campaign. Despite his significant contributions, a lack of personal papers left him in obscurity. Authors Frank Simione Jr. and Gene Schmiel used available sources to create a reliable and readable synthesis of the man and his career to fill a sizable gap in the historiography. Unless or until his private papers surface, Searching for Irvin McDowell will stand as the best treatment available.