Despite the island's expansion, little development happened immediately, but significant construction occurred during World War I. Governors Island is sometimes mentioned as the location of the United States' first overt military action during the war, on April 6, 1917, when troops from the island captured German vessels in New York Harbor minutes after the U.S. Congress declared war on Germany. Barracks, tents, and temporary wooden buildings were built on the original northern portion of the island, while the new southern section housed warehouses and other ancillary facilities which collectively stored $75 million worth of material. The structures were all connected by the Governors Island Railroad, which consisted of numerous sidings for shunting. The railroad had been reduced to and was dubbed the "World's Shortest Railroad" by the time it was torn up in 1931, though a train chassis remained buried on the island through the 2010s.