When the American Revolutionary War broke out in 1775 , the city of Charleston in the colony of South Carolina was a center of commerce in southern North America . The city 's citizens joined other colonists in opposing the British parliament 's attempts to tax them , and militia recruitment increased when word arrived of the April 1775 Battles of Lexington and Concord . Throughout 1775 and into 1776 , militia recruits arrived in the city from the colony 's backcountry , the city 's manufacturers and tradesmen began producing war materiel , and defensive fortifications began to take shape around the city .