Some of the Ticonderoga cannons, which are of a size and range not previously available to the Americans, are emplaced in fortifications around the city, and on the night of March 2, the Americans had begun to bombard the city with those cannon, to which the British had responded with cannonades of their own.

The American guns, under the direction of Colonel Knox, had continued to exchange fire with the British until March 4.

The exchange of fire has done little damage to either side, although it has damaged houses and killed some British soldiers in Boston.

On March 5, Washington had moved more of the Ticonderoga cannon and several thousand men overnight to occupy Dorchester Heights, overlooking Boston.

Since it is winter the ground is frozen, making the digging of trenches impractical.

Washington's men instead use logs, branches and anything else available to fortify the position overnight.

The British fleet is within range of the American guns on Dorchester Heights, putting it and the troops in the city at risk.

The immediate response of the British is a two-hour cannon barrage at the heights, which has no effect because the British guns cannot reach the American guns at such height.

After the failure of the barrage, Howe and his officers agree that the colonists must be removed from the heights if they are to hold Boston.

They plan an assault on the heights; however, due to a storm the attack will never take place, and the British elect instead to withdraw.