The 123rd Pennsylvania Infantry was an infantry regiment formed in western Pennsylvania for service in the Union Army during the American Civil War. It served in the Eastern Theater in a number of campaigns and battles with the Army of the Potomac, but perhaps it should be most noted for its gallant charge against Marye's Heights during the Battle of Fredericksburg.
- Lang, Scott B. The Forgotten Charge: The 123rd Pennsylvania at Marye's Heights, Fredericksburg, Virginia. Shippensburg, Pennsylvania: White Mane Publishing Company, 2002. ISBN 1-572492-92-9.