The most famous dance of the 1920s is named after a city it did not premiere in. The Charleston became a hit on Broadway, but its name points to the docks of South Carolina.
The dance took off with Runnin' Wild, a Broadway revue with an African American cast that opened in late October 1923. Its song "Charleston" had music by James P. Johnson and lyrics by Cecil Mack. Etymonline records Charleston as a song title in 1923 and as the name of a dance by 1925.
Johnson said he got the rhythm from South Carolina longshoremen who had moved to New York. He played piano in a club full of former Charlestonians and improvised music to fit their footwork and handclapping. The Charleston historian Nic Butler notes how much that rhythm resembles the ring shout tradition of the Lowcountry.
Charleston itself has another candidate. The Jenkins Orphanage, which grew out of an aid society founded in 1891, had a band of young boys. They headed north every summer and played mostly on street corners for pennies and nickels. Local musicians have long believed those boys carried the dance north. Butler calls this quite possible, but fires in 1936 and 1988 destroyed most of the orphanage's early records. In 1924 a New York World story, reprinted in Charleston, reported that the dance "is said to have been brought to New York" by former residents.
The city's own name is simpler. It was founded in 1670 as Charles Town, named for King Charles II of England, and moved to its present peninsula in 1680. Charles itself goes back to a Germanic word meaning roughly "man."
The modern spelling arrived late. For 113 years clerks wrote it four ways: Charles Town and Charlestown, each with or without a final e. No known text uses the form Charleston before August 13, 1783, when an act incorporated the town as a city. The city's leaders left no explanation for the change.
The war with Britain had just ended, so a snub to the king is a tempting explanation. Butler does not make that argument. His reading is that dropping "Town" marked the place's new status as a city.