The spelling morphed from the original Charles Town(e) to the now-standard Charleston over more than a century. The Revolution years were a transitional time — I have seen it written every which way in accounts from the 1770s and 1780s. While Charles Town and Charlestown were most common in the period, Charles Towne still appeared occasionally and Charleston was already in use. Charlestown and Charleston seem to have become more prevalent as the war progressed. I suspect the official naming reflected the most common usage when the city was incorporated in 1783. The issue is complicated by the lack of standards and well-intentioned later authors “clarifying” the original text to make the reading easier for their audiences. I recall seeing some histories written in the 19th Century using Charleston without regard to the original language in quotations.

Here are some of the various usages in the Revolutionary era: A London newspaper spelled it Charles Town in 1776 and a Charleston newspaper spelled it Charles-Town in 1777. (The dash also appeared frequently in South-Carolina.) The local almanac was an early adopter, spelling it Charleston in 1776. A quick check of some histories written by participants reveals that Ramsay (American doctor and politician) used Charleston in 1785; Stedman (British officer) used Charlestown in 1794; Moultrie (American officer and politician) and Drayton (American politician) used Charlestown in 1802 and 1821. Maps from the 1770s and 1780s most commonly used Charlestown or Charles Town. Richard Hutson, who was in the patriot militia during the Battle of Sullivan’s Island, became the first intendant (mayor) of Charleston in 1783. He spelled it Charles Town in letters written during and after the battle of Sullivan’s Island in 1776.