George Washington's Engineer

In January 1776, George Washington had a problem: the British army controlled the city of Boston. The colonial army needed to force the British to leave. But how? Washington had a solution: ask his engineer Rufus Putnam to solve the problem. They needed to take control of the high ground, Dorchester Heights, just south of Boston. They could place cannons there to bombard the British army. But the ground was frozen solid. A story of courage and engineering to win a battle.