In 1872, there were more than 300,000 slaves in Cuba and Puerto Rico. Though the Spanish government had passed a law for gradual abolition in 1870, slaveowners, particularly in Cuba, clung tenaciously to their slaves as unfree labour was at the core of the colonial economies. Moreover, the Spanish bourgeoisie was deeply implicated in colonial slavery as Spain was the last European power to abolish the slave trade and bonded labour in the Americas.