The five Montana-class battleships, leviathans designed to dwarf even the giant Iowa-class battleships, were authorized for construction but never built, victims of the ascendance of naval aviation. Nearly as large as a modern supercarrier the Montana-class, like all battleships, was made obsolete by the success of the aircraft carrier. This first appeared earlier and is being reposted due to reader interest. In the late 1930s, the U.S. government, recognizing the deteriorating world situation, sought to rebuild U.S. naval power. The crash of the stock market in October 1939, as well as the Washington and London naval treaties, had slowed the growth of the U.S. Navy and reduced its tempo of peacetime operations. By 1940, however, with fighting raging in Asia and Europe, it was clear the United States needed to beef up its defensive capability to deter attack—or to prosecute a war if it were dragged into conflict.