The abolition of slavery in the British Empire in 1833 included slaves in North America. The emancipated blacks prospered, gained education and experienced a rapid upward social mobility, by the twentieth century, becoming a mainly middle class community. Conversely, the Irish-American community remained a predominantly poor, working class population, subsisting on hard physical labor such as the coal mining on which the North American Union depended for its energy. This created a feeling of bitter jealousy among the Irish, and many of them came to support the Sons of Liberty, a terrorist organization that wants to see America become independent from the British Empire and promotes a blatantly racist and xenophobic ideology.