You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Charleston,_South_Carolina

Context:
By the mid-18th century, Charles Town had become a bustling trade center, the hub of the Atlantic trade for the southern colonies. Charles Towne was also the wealthiest and largest city south of Philadelphia, in part because of the lucrative slave trade. By 1770, it was the fourth-largest port in the colonies, after Boston, New York, and Philadelphia, with a population of 11,000—slightly more than half of them slaves. By 1708, the majority of the colony's population was slaves, and the future state would continue to be a majority of African descent until after the Great Migration of the early 20th century.

Question:
What lucrative trade contributed greatly to Charles Town's growth?

slave trade