What was the only way Washington could defeat British forces

With the arrival of heavy guns from Fort Ticonderoga, Washington made the bold decision to place these artillery pieces upon Dorchester Heights. From this lofty position Washington could target the British ships in Boston harbor. British attempts to deny the American's this position failed and the British forces departed Boston on March 17, 1776.

i think iowa because you committed the crime there

where is the passage

i cant solve it without knowing the passage