"Old Ironsides," one of the U.S. Navy's six original frigates, never lost a battle. The ship was constructed in the North End from 1794 to 1797 at a cost of $302,718, using bolts, spikes, and other fittings from Paul Revere's foundry. As the new nation made its naval and military reputation, the Constitution played a key role, battling French privateers and Barbary pirates, repelling the British fleet during the War of 1812, participating in 40 engagements, and capturing 20 vessels. The frigate earned its nickname during an engagement on August 19, 1812, when shots from the French warship Guerriere bounced off its thick oak hull as if it were iron. Today, the active-duty sailors who lead tours wear 1812 dress uniforms.

Retired from combat in 1815, the Constitution was rescued from destruction when Oliver Wendell Holmes's poem Old Ironsides launched a preservation movement in 1830. The frigate was completely overhauled for its bicentennial in 1997, when it sailed under its own power for the first time since 1881, drawing international attention. Tugs tow the Constitution into the harbor every Fourth of July and turn it to ensure that the ship weathers evenly.

To continue on the Freedom Trail: Walk straight ahead to the museum entrance.