The US Navy's most modern destroyers as it entered World War II were 100 ships from eleven classes introduced in the 1930s: 1,500-tonners and 1,850-ton destroyer leaders designed to conform to the 1930 London Naval Treaty, plus the successor 1,570-ton Sims class and the first-commissioned 1,620- and 1,630-tonners of the Benson and Gleaves classes. Collectively, these destroyers carried the Navy through the war's first year when the outcome was in doubt: while most 1,500-tonners and leaders were assigned to front line duty in the Pacific before being relegated to secondary assignments, the later Bensons and Gleaves became the standard destroyers for Atlantic and Mediterranean operations and remained prominent in the Pacific throughout the war. This volume describes the fascinating design story behind these developmental classes – from the constraints of peacetime treaties to advances in propulsion engineering and wartime modifications. With an operational overview of their service and tables listing all 169 ships by class, builder, and initial squadron, this is a definitive guide to the pre-war US destroyer classes.