Slavery in Maryland lasted around 200 years, from its beginnings in 1642 when the first Africans were brought as slaves to St. Mary's City, Maryland, to the final elimination of slavery in 1864 during the penultimate year of the American Civil War.
Initially, Maryland colonists developed the use of slaves in ways similar to neighboring Virginia. The early settlements and population centers of the province tended to cluster around the rivers and other waterways that empty into the Chesapeake Bay. Maryland planters cultivated tobacco as the chief commodity crop, as the market was strong in Europe. Tobacco was labor-intensive in both cultivation and processing, and planters struggled to manage workers as tobacco prices declined in the late 17th century, even as farms became larger and more efficient. At first, indentured servants from England supplied much of the necessary labor but, as their economy improved at home, fewer made passage to the colonies. Maryland colonists turned to importing indentured and enslaved Africans to satisfy the labor demand.
By the 18th century, Maryland had developed into a plantation colony and slave society, requiring vast numbers of field hands for the labor-intensive commodity crop of tobacco. In 1700 the province had a population of about 25,000, and by 1750 that number had grown more than 5 times to 130,000. By 1755, about 40% of Maryland's population was black, with African Americans concentrated in the Tidewater counties where tobacco was grown. An extensive system of rivers facilitated the movement of produce from inland plantations to the Atlantic coast for export. Baltimore was the second-most important port in the eighteenth-century South, after Charleston, South Carolina. In the first two decades after the war, a number of slaveholders freed their slaves. In addition, free families of color had started during the colonial era with mixed-race children of unions between white women and African men. By the time of the Civil War, slightly more than 49% of the blacks and people of color in Maryland were free.