Maryland’s State House is the oldest one still used regularly by a legislature. Started in 1772, the building wasn’t totally finished until 1797. A lot happened during those 25 years to delay construction, including at least one hurricane and the Revolutionary War. From November 1783 to August 1784, the Continental Congress met in the unfinished state house, using it to sign the Treaty of Paris that ended the Revolutionary War.
Nickname: The Old Line State
Statehood: April 28, 1788