The United States entered World War I in April 1917. Within days, the federal government created the U.S. Shipping Board Merchant Fleet Corporation (also known as the Emergency Fleet Corp. or EFC) to construct a fleet of merchant ships. The EFC hired the American International Shipbuilding Corporation to build and operate the largest shipyard in the world, Hog Island, near Philadelphia.
At its peak, Hog Island employed some 30,000 workers and launched a vessel every 5½ days. Its workers built 122 ships in four years, and although none saw service before the end of the war, many carried supplies during World War II. At Hog Island, the United States learned how to build large ships quickly on a grand scale from prefabricated parts.
This enameled lapel pin or tie tack indentified the wearer as associated with the U.S. Shipping Board Emergency Fleet Corporation.