Complex sentence: At the beginning of the 18th century 27,817 African people were enslaved in British North America but the agricultural opportunities in the British colonies increased the demand for slave labor and throughout the 18th century the number of Africans enslaved in North America steadily increased.
Split into simpler sentences: At the beginning of the 18th century 27,817 African people were enslaved in British North American colonies. The agricultural opportunities in the British colonies increased the demand for slave labor and throughout the 18th century the number of Africans enslaved in North America steadily increased.