The Iowa-class battleships were six battleships ordered by the United States Navy in 1939 and 1940 to escort the Fast Carrier Task Forces that would operate in the Pacific Theatre of World War II. Four were completed in the early to mid-1940s; two more were laid down, canceled prior to completion, and ultimately scrapped. They comprised the final class of U.S. battleships to be built.Built with no regard for cost, the Iowa class was arguably the ultimate in the evolution of the capital ship. The ships topped the Discovery Channel's list of the ten "most fearsome vessels in the history of naval warfare." Yet even as these leviathans entered service, they were being eclipsed by aircraft carriers as the most important naval vessels.The Iowa-class battleships served in every major U.S. war of the latter half of the 20th century. In World War II, they defended aircraft carriers and shelled Japanese positions before being placed in reserve at the end of the war. Recalled for action during the Korean War, the battleships provided artillery support for UN forces fighting against North Korea. In 1968, New Jersey was recalled for action in the Vietnam War and shelled Communist targets near the Vietnamese Demilitarized Zone. All four were reactivated and armed with missiles during the 1980s as part of the 600-ship Navy. In 1991, Missouri and Wisconsin fired missiles and 16-inch (406 mm) guns at Iraqi targets during the Gulf War. All four battleships were decommissioned in the early 1990s, and were removed from the Naval Vessel Register in 2006.