The Spanish saw the potential for a “cash cow” in Europeans’ insatiable need for the sweet stuff, so it was the development of the sugar industry that fueled the slave trade. But with the Taíno population dwindling, the Spanish turned to Africa and began importing slaves. In 1522, the first slave revolt took place, right on Diego Columbus’s plantation. Unfortunately, the slaves were horribly massacred. Nearly a half million slaves were brought to Hispaniola between 1520 and 1801. They made the trip in the bellies of galleons, chained together for a horrendous three-month voyage to the Caribbean—a trip that would leave many dead before arrival. Then they had to suffer the incomparable horrors of slavery, being denied their culture and identities, all for the gain of European wealth.
The slave trade was a triangle, literally. Boats set out from various European ports toward Africa’s west coast with goods they would use in a trade for people. Once they loaded their slaves onto the ships, they would journey to the Caribbean, where the ones who survived were sold. The ships then returned to Europe with sugar, coffee, tobacco, rum, and rice, all produced by slave labor.
Spanish fortunes were made through the sugar and triangular trade industry, and England and France got jealous. As pirates and buccaneers got wind of the riches, they went with the blessings of (and sometimes funded by) their countries to impede the successes of the industry. One famous incident was when Sir Francis Drake and his 18 ships of men, sent by England, took over Santo Domingo  and held it for ransom for a month. When the Spanish finally paid, he looted and burned the entire city before leaving.
The French, on the other hand, in a bold move sent over 13,000 men (farmers and African slaves) to populate the poorly guarded western half of the island. Eventually, the population of their colonies greatly outnumbered that of the Spanish side, making the Spanish incredibly uneasy; in fear of losing control of the rest of the island they agreed to a border treaty called the Treaty of Ryswick (1697), which officially ceded the western portion of Hispaniola to France. It was named Saint-Domingue and the Spanish side was named Santo Domingo. The border that was created is more or less the same today.