Increasing self-government has marked St Lucia's 20th-century history. A 1924 constitution gave the island its first form of representative government, with a minority of elected members in the previously all-nominated legislative council. Universal adult suffrage was introduced in 1951, and elected members became a majority of the council. Ministerial government was introduced in 1956, and in 1958 St. Lucia joined the short-lived West Indies Federation, a semi-autonomous dependency of the United Kingdom. When the federation collapsed in 1962, following Jamaica's withdrawal, a smaller federation was briefly attempted. After the second failure, the United Kingdom and the six windward and leeward islands—Grenada, St. Vincent, Dominica, Antigua, St. Kitts and Nevis and Anguilla, and St. Lucia—developed a novel form of cooperation called associated statehood.