Complex sentence: Over the night of March 4,1776, as 800 American soldiers stood guard along the river below Dorchester shores, 1200 American soldiers took Dorchester Heights uninhibited and began working through the night to build structures suitable to defend against the British Army.
Split into simpler sentences: Over the night of March 4,1776, as 800 American soldiers stood guard along the river of Dorchester shores, 1200 American soldiers took Dorchester Heights uninhibited. They began working through the night to build structures suitable to defend against the British Army.