The Mangum Plate consists of three fragments of elaborately embossed copper sheeting formed of separate parts overlapped and hammered together and riveted where necessary. The pieces were found in 1936 by Spurgeon C. Mangum on a knoll situated on his farm 5 miles northeast of Port Gibson, Mississippi, 1 mile south of Bayou Pierre (R 3E, Tn 12N, S 28). The site has since been acquired by the State of Mississippi for the National Park Service for development as a feature of archaeological interest along the Natchez Trace Parkway.