The Gadsden Purchase half dollar was a proposed commemorative coin to be issued by the United States Bureau of the Mint. Legislation for the half dollar passed both houses of Congress in 1930 but was vetoed by President Herbert Hoover. The House of Representatives sustained his action, 96 votes in favor of overriding it to 243 opposed, well short of the necessary two-thirds majority. This was the first veto of Hoover's presidency and the first ever for a commemorative coin bill.
The proposal to commemorate the 1854 congressional ratification of the Gadsden Purchase was the brainchild of El Paso coin dealer Lyman W. Hoffecker, who wanted a commemorative coin he could control and distribute. He gained the support of several members of Congress from Texas and the Southwest, and a bill was introduced in Congress in April 1929, receiving a hearing 11 months later. Treasury Secretary Andrew W. Mellon sent a letter and two officials in opposition to the bill, but it passed both houses of Congress without dissent. On April 21, 1930, Hoover vetoed the bill, deeming commemorative coins abusive. Although only one congressman spoke in favor of Hoover's action during the override debate in the House, the veto was easily sustained.
No commemorative coins were struck during the remainder of the Hoover Administration. They resumed after Franklin D. Roosevelt was inaugurated, but by 1935 Roosevelt was citing Hoover's veto in urging Congress to avoid passing commemorative coin bills. He vetoed one in 1938. In 1946, Harry S. Truman adopted similar arguments in warning he would oppose further coin bills, and he vetoed one in 1947. Dwight D. Eisenhower vetoed three more in 1954. No non-circulating commemorative coins were struck from 1955 until after the Treasury Department changed its position in 1981.