What mistake did the British make early in the Revolutionary War during the battle for New York City?

Early in the Revolutionary War, during the battle for New York City, the British made the mistake of underestimating the determination and resilience of the Continental Army led by George Washington. They assumed a quick victory due to their superior numbers and training, leading to overconfidence. Additionally, their strategy was hampered by poor communication and coordination among their forces, allowing the Americans to exploit weaknesses and conduct a strategic retreat. This initial miscalculation allowed Washington to preserve his army and continue the fight.