Question: what caused the american defeat in new york in 1776

title: Battle of Long Island
text: On August 22 , the British landed on the shores of Gravesend Bay in southwest Kings County , across the Narrows from Staten Island and more than a dozen miles south from the established East River crossings to Manhattan . After five days of waiting , the British attacked American defenses on the Guan Heights . Unknown to the Americans , however , Howe had brought his main army around their rear and attacked their flank soon after . The Americans panicked , resulting in twenty percent losses through casualties and captures , although a stand by 400 Maryland troops prevented a larger portion of the army from being lost . The remainder of the army retreated to the main defenses on Brooklyn Heights . The British dug in for a siege but , on the night of August 29 -- 30 , Washington evacuated the entire army to Manhattan without the loss of supplies or a single life . Washington and the Continental Army were driven out of New York entirely after several more defeats and forced to retreat through New Jersey and into Pennsylvania . 

Answer: answer: After five days of waiting, the British attacked American defenses on the Guan Heights. Unknown to the Americans  Howe had brought his main army around their rear and attacked their flank soon after.  Washington and the Continental Army were driven out of New York entirely after several more defeats and forced to retreat through New Jersey and into Pennsylvania.