After the Revolutionary War, a number of large plantations were established throughout Glynn County. Because conditions in the area were favorable for the cultivation of rice and cotton several planters with hundreds of slaves settled in the vicinity during the 1790s. By the early 19th century, a large proportion of the county had been made into about two dozen large plantations that were owned by aristocratic gentlemen planters who built fine homes and gardens where they received several national and international guests. On the Mainland, the Altamaha River plantations of Hopeton, Altama, Elizafield, Evelyn, Grantley, Broadfield, and Hofwyl were the center of rice And sugar production in the region. The Hopeton-Altama Plantation, owned by James Hamilton Couper, was a rice and sugar plantation where many early agricultural innovations were developed and practiced. It was at Hopeton that Couper pioneered the extraction and refining of sugar from the ribbon cane.
During this time St. Simons Island was divided into fourteen plantations. Of these plantations, the Couper Plantation, Hampton Plantation at Butler’s Point, Hamilton Plantation at Gascoigne Bluff, and Retreat Plantation were the largest and most well known. Around 1795 a long staple cotton known as Sea Island cotton was introduced into cultivation and the plantations flourished. The wharf of Hamilton Plantation at Gascoigne Bluff became the shipping center of the island where the sea island cotton was loaded on vessels bound for markets in Europe. With the new settlers coming into the country, Brunswick experienced a return to growth and prosperity. Brunswick, with its fine natural harbor, was made an official port of call in 1789. Efforts were made by the city fathers to build Brunswick into a shipping and commercial center that would rival Savannah. A newspaper, a bank, a hotel and other amenities that would be found in a modern port town of the day were established.
In 1838 work began on the Brunswick Altamaha Canal, an enterprise aimed at redirecting trade on the Altamaha to Brunswick. The canal opened in the 1850s at which time construction was started on the first railroad to Brunswick.
Glynn County’s prosperity was interrupted by war, this time by the War Between the States. A Union blockade of the coast of Glynn County cut off all shipping and seaborne supplies. All agriculture and commerce stopped. In 1861 the residences of Brunswick were ordered to evacuate the town and in 1862, Brunswick was occupied by the Union. The plantations along the Altamaha were abandoned by their owners and were confiscated by Union forces.