<P> Alongside sugarcane, the cacao (cocoa) crop also contributed greatly to economic earnings in the late nineteenth and early twentieth centuries . In the 1920--1930 period, the collapse of the sugarcane industry concomitant with the failure of the cocoa industry resulted in widespread depression among the rural and agricultural workers in Trinidad, and encouraged the rise of the Labour movement . This movement was led by Arthur Cipriani and Tubal Uriah "Buzz" Butler, who, in combination with his Indian partners (notably Adrian Cola Rienzi), aimed to unite the working class and agricultural labour class to achieve a better standard of living for them, as well as to hasten the departure of the British . This effort was severely undermined by the British Home Office and by the British - educated Trinidadian elite, many of whom were descended from the plantocracy themselves . They instigated a vicious race politicking in Trinidad aimed at dividing the class - based movement on race - based lines, and they succeeded, especially since Butler's support had collapsed from the top down . </P> <P> Petroleum had been discovered in 1857, but became economically significant only in the 1930s and afterwards, as a result of the collapse of sugarcane and cocoa, and increasing industrialization . By the 1950s, petroleum had become a staple in Trinidad's export market, and was responsible for a growing middle class among all sections of the Trinidad population . The collapse of Trinidad's major agricultural commodities, followed by the Depression, and the rise of the oil economy, led to major changes in the country's social structure . </P> <P> Trinidad and Tobago gained its independence from the United Kingdom on 31 August 1962 . Elizabeth II remained head of state as Queen of Trinidad and Tobago . Eric Williams, a noted Caribbean historian, widely regarded as The Father of The Nation, was the first Prime Minister; he served from 1956 to 1959, before independence as Chief Minister, from 1959 to 1962, before independence as Premier, from 1962 to 1976, after independence as Prime Minister of the Commonwealth of Trinidad and Tobago, then from 1976 to his death in 1981 as Prime Minister of the Republic of Trinidad and Tobago . Rudranath Capildeo was the first Leader of the Opposition post-independence; he served from 1962 to 1967 . </P> <P> The presence of American military bases in Chaguaramas and Cumuto in Trinidad during World War II profoundly changed the character of society . In the post-war period, the wave of decolonisation that swept the British Empire led to the formation of the West Indies Federation in 1958 as a vehicle for independence . Chaguaramas was the proposed site for the federal capital . The Federation dissolved after the Jamaican Federation of the West Indies membership referendum of 1961, and the resulting withdrawal of the Province of Jamaica . The government of Trinidad and Tobago then also chose to seek independence from the United Kingdom on its own . </P>

When did trinidad and tobago gain its independence