This 1917 photograph from a Mare Island photo album shows a U.S. Navy sailor in period undress white uniform, complete with the traditional flat hat and neckerchief, standing outside a barracks building at the Mare Island Naval Shipyard. Located in Vallejo, California, Mare Island served as a key West Coast Navy shipyard and training station during World War I, processing thousands of sailors as the United States mobilized its fleet for the war effort. Project: 218551