The islands of Antigua and Barbuda were populated by Arawak-speaking people from at least 1000 BC. By 1493, when Columbus passed Antigua, it was occupied by Carib Indians. English settlers arrived in 1632. Sugar plantations, using slave labour, were established in the 1650s. As British colonies, Antigua and Barbuda formed part of the Leeward Islands Federation from 1871 until 1956 when they became a separate Crown Colony. This was merged into the West Indies Federation from Jan. 1958 until May 1962 and became an Associated State of the UK on 27 Feb. 1967. Antigua and Barbuda gained independence on 1 Nov. 1981.