In the late 1600s sugarcane became the primarily crop on the islands after Sir Christopher Codrington established sugarcane plantations with much success. With this new cash crop under British presence and diminished native populations due to disease, Africans were brought in to work the land as slaves; of the few remaining Caribs, many died in this new wave of foreign diseases from Africa. The major crops grown on the islands shifted from tobacco, indigo, and sugarcane to almost exclusively sugarcane. To produce these products much manual labor was needed, making the islands dominated by people of African descent and smaller numbers of British land owners.
In the 1700s Antigua & Barbuda became the center of the British Caribbean naval fleet. This hurt the local economy since the major importer of their sugarcane was the United States; a law outlawing the export of any good from a British colony to the United States essentially shut down the economy for some time.
In 1834 the slaves of Antigua & Barbuda were freed, but all land was owned by the British landowners so these former slaves remained dependent on their former owners. This situation changed little until 1946 when the workers formed unions and gained political power. From this point on, the workers have controlled the government, but they didn't gain true control over the government until 1981 when the islands gained independence from Britain (but remained a part of the Commonwealth).
Since 1981 little has changed in Antigua & Barbuda other than a growing tourism industry and the purchasing of houses by American celebrities on the islands.