Settled by indigenous cultures for thousands of years, the islands were an early site of the Spanish founding of colonialmissions. Historically the Spanish influenced the Guale and Mocamachiefdoms by establishing missions in their major settlements, from St. Catherine's Island south to Fort George Island (at present-day Jacksonville, Florida). Both chiefdoms extended to the coastal areas on the mainland. The Mocama Province included territory to the St. Johns River in present-day Florida. The system ended under pressure of repeated raids by English South Carolina colonists and Indian allies. Spain ceded its territory of Florida to Great Britain in 1763 following the British victory against the French in the Seven Years War.
After 18th-century European-American settlement of Georgia and Florida, planters imported enslavedAfricans as laborers. Many were used to work the labor-intensive cotton, rice and indigoplantations on the Sea Islands. The slaves developed the notable and distinct Gullah/Geechee Creole culture and language which has survived to contemporary times. The islands now are known for resort, recreational, and residential development.
During the American Civil War, the Union Navy and the Union Army soon occupied the islands. The white planter families had fled to other locations on the mainland, sometimes leaving behind their slaves. The blacks largely ran their own lives during this period. They had already created cohesive communities, because planter families often stayed on the mainland to avoid malaria and isolation. Large numbers of slaves worked on the rice and indigo plantations, and they had limited interaction with whites, which had enabled them to develop their own distinct culture. During the war, the Union Army managed the plantations and assigned plots of land to slaves for farming.
After President Abraham Lincoln's Emancipation Proclamation was effective on January 1, 1863, more than 5,000 slaves on Union-occupied islands obtained their freedom. After the war, although the freedmen hoped to be given land as compensation for having worked it for so many years in slavery, the federal government generally returned properties to the planter owners returning from their refuges or exiles. Many of the freedmen stayed in the area, working on their former plantations as sharecroppers, tenant farmers or laborers as the system changed to free labor.