The Old Exchange Building was established as one of the three most historic buildings in colonial America. Delegates to the Continental Congress were elected in this building. The United States Constitution was ratified upstairs in the Great Hall. The Declaration of Independence was publicly read to the citizens of Charleston in 1776 AD. During the British occupation from 1780 AD to 1782 AD, the basement of the building was used as a prison, which earned it the infamous nickname "The Dungeon".