A fictionalized account of a daring event from the Revolutionary War. During the winter 1775-76, General George Washington needs guns and ammunition to help reclaim the city of Boston, blockaded by the British. Colonel Henry Knox and his brother Will decide to move 183 cannons from New York's Fort Ticonderoga, captured by the Americans the previous May, to Boston. However, this means moving the guns over mountainous wilderness in snow and mud, while keeping their efforts secret from the British.