Dorchester County was named for Dorchester, Massachusetts. In 1696 Congregationalists from that town moved south and established a new settlement called Dorchester. Although the town of Dorchester had been abandoned by 1788, the parish in which it was located continued to be referred to as St. George Dorchester. This name was subsequently adopted for the county when it was formed from parts of Colleton and Berkeley counties in 1897. The county seat is the town of St. George, which also took its name from the old parish. The town of Summerville was settled in the late eighteenth century as a summer resort for planters who wished to escape the malaria prevalent on their rice plantations; the town later became a winter resort as well. Middleton Place Gardens, the remains of an old rice plantation, are the oldest landscaped gardens in the country, having been laid out in 1741. Middleton Place was the home of Henry Middleton (1717- 1784), president of the Continental Congress, his son Arthur Middleton (1742-1787), a signer of the Declaration of Independence, and his grandson Henry Middleton (1770-1846), a governor, United States Congressman, and ambassador to Russia.
The home of Joseph Koger Jr., (Ca 1790s), is the oldest residence remaining in Upper Dorchester County. Joseph Koger, Jr. served in the SC House (1806-1812), first sheriff of Colleton County (1813-1817) and served in the SC Senate (1818-1838). Restoration of the house was completed in October 2009 by the Upper Dorchester County Historical Society.
All information provided by the Upper Dorchester County Historical Society.