The Louisiana Purchase Sesquicentennial half dollar was a proposed United States commemorative coin. Intended for the 150th anniversary of the Louisiana Purchase, the coin was lobbied for by the Missouri Historical Society (MHS) and the Louisiana Purchase 150th Anniversary Association of New Orleans, led by Clay Shaw; they hoped to be able to buy the entire coin issue from the government and sell it at a profit. Numismatist Eric P. Newman advocated for the bill on behalf of the MHS. The House of Representatives passed authorizing legislation in April 1953, but the Senate was slower to act, passing it in January 1954. The Treasury Department strongly opposed the bill, and President Dwight D. Eisenhower vetoed it and two other commemorative coin bills on February 3, 1954; Congress made no attempt to override the vetoes. No commemorative coins were authorized or issued by the United States after 1954 until a new issue was authorized in 1981. (Full article...)