 Construction of the original fort began in 1643 and it saw use as a military installation into the 20th century.Fort Miller (Fort Darby prior to the Civil War) in Marblehead also defended Salem's harbor from the 1630s through the American Civil War.Fort Pickering is a First System fortification named for Colonel Timothy Pickering, born in Salem, adjutant general of the Continental Army and secretary of war in 1795.