The first South Dakota class was a group of six battleships that were laid down in 1920 for the U.S. Navy, but were never completed; designed to achieve , they represented an attempt to catch up with the increasing fleet speeds of its main rivals, the British Royal Navy and Imperial Japanese Navy.
The South Dakotas were authorized in 1917, but work was postponed so that the U.S. Navy could incorporate information gained from the Battle of Jutland, fought in mid-1916, in their design. Work was further postponed to give destroyers and other small fighting vessels priority as they were needed urgently to fight German U-boats in the North Atlantic. Construction started only in 1920. As the Washington Naval Treaty of 1922 both restricted the total battleship tonnage allowed the U.S. Navy, and limited individual ship size to , construction was halted in early 1922. The unfinished hulls were scrapped the following year, the guns were transferred to the U.S. Army and their boilers and armor were used to modernize older battleships.
Background and design history
Before World War I began in August 1914, the Navy was not well funded by the U.S. Congress, which had failed to heed the General Board's recommendation of a building program of two battleships per year. The election of President Woodrow Wilson in 1912 and his appointment of Josephus Daniels as Secretary of the Navy did nothing to change that as neither man believed that additional expenditures on the Navy were worthwhile. The start of the war began to change that attitude and, in early 1915, the General Board called for construction of four battleships in Fiscal Year (FY) 1916, although the Committee on Naval Affairs rejected that recommendation on the basis that it was not prudent to make changes to the existing program before enough had been learned from the experiences of the war. In parallel with this there arose a belief that a victorious Imperial Germany might be able to invade the United States, including a movie that showed victorious Germans executing Civil War veterans, and that the Navy was unprepared to deal with such a threat.
Events abroad like the Japanese Twenty-One Demands on China in early 1915, German attempts to begin unrestricted submarine warfare and the sinking of the Lusitania in May exposed US weaknesses to the public eye. They caused Wilson to reconsider his position and he ordered the Secretaries of War and Navy to plan for mobilization in July. The General Board argued that the Navy should be the equal to the strongest navy in the world, that of the British, not just to the most likely enemy, Imperial Germany, and advocated for construction of 10 battleships over five years, together with battlecruisers and smaller ships. Congress was debating the appropriation bill while the Battle of Jutland occurred in at the end of May 1916 and the British victory confirmed the value of the battleship in eyes of the Congressmen. They compressed the General Board's program into three years with four ships in FY 1917 and three in each of the following years. The first four ships, which became the Colorado class, were only modest improvements over the preceding , but the changed attitude towards battleships allowed the General Board to propose much more powerful, and expensive, ships for the last two batches. The maximum price was set at $21,000,000.