The flag of Maryland is the heraldic banner of arms of Cecil Calvert, 2nd Baron Baltimore and dates back to the 17th century. The Maryland flag remains the only state flag in the United States of America that is a heraldic banner and represents the Baltimore family who were once the proprieters of the state. The flag of Maryland was officially adopted on 9 March 1904. The flag's ratio is 2:3.
A large Maryland flag flies at a Baltimore Ravens game