Charles Thomas Cassatt was born July 15, 1893 in Cumberland Township, in a house, no longer standing, directly across Taneytown Road from the current Gettysburg National Military Park Maintenance Building. He was one of nine children belonging to Jefferson Thomas and Margaret Schrum Cassatt.
He was working as a farm laborer near Bordentown, NJ, when he registered for the draft in June of 1917. He entered military service in March of 1918, and was stationed at Camp Dix, NJ. Private Cassatt was a member of 309th Infantry, 78th Division Medical Department, sailing for duty overseas May 20, 1918. He served on the front lines during the fighting at Verdun and in the Argonne Forest, also on the Alsace-Lorraine Forest.