Seamen's Protection Certificates were authorized by Congress in 1796 to identify American merchant seamen as citizens of the U.S. and as such entitled to protection against impressment by the British Navy, a major cause of the War of 1812. Certificates were issued long after that conflict, in fact right up to the Civil War, and they constitute an important proof of citizenship for the highly mobile merchant seaman. This is the third volume in a series of indexes to early merchant seamen's records. This index covers a dozen ports with the records ranging from 4,400 applications for the Port of New Orleans to eighteen such proofs for New London, Connecticut.