The Republic of Massachusetts was an independant republic that existed from July to September 1815. The Republic of Massachusetts was originally the state of Massachusetts, a part of the United States of America. The Republic of Massachusetts seceded four months after the Redeclaration in March 1815, which restarted the War of 1812. Massachusetts was invaded by the British Empire three months after it seceded, which took the capital Boston easily as the United States Army had withdrawn. The British did not learn until after the Battle of Boston that Massachusetts was an independant republic. Regardless, they kept it as it was originally one of their colonies.