Jackson first saw action near Charleston in June 1776, when his regiment fought off General Sir Henry Clinton's attempted attack on Fort Sullivan. The unit then spent a long period garrisoning the city of Charleston, during which Charles Cotesworth Pinckney assumed command of the 1st South Carolina. Late in 1777, Jackson was part of the detachment that made an ill-conceived and worse conducted expedition against St. Augustine in British East Florida under Major-General Robert Howe. The expedition was a colossal failure, and the American force was struck down by disease. Jackson survived, and returned to South Carolina in 1778.