Which battle was the first major confrontation of the Revolutionary War showcasing American resilience?

The Battle of Bunker Hill, fought on June 17, 1775, is often recognized as the first major confrontation of the American Revolutionary War that highlighted the resilience of the American forces. Even though the battle took place on Breed's Hill, the name Bunker Hill is commonly used to refer to this encounter.

This battle demonstrated that colonial militia could stand up to the professional British army, showcasing their determination and fighting spirit. Despite ultimately losing the ground, American forces inflicted significant casualties on the British troops, indicating that the conflict would not be easily won by the British and boosting the confidence of the colonial fighters. The high number of British casualties relative to their numbers solidified the idea that the colonies could contest British military power effectively, serving as a rallying point for further resistance.

The other battles listed do have their significance in the overall conflict, but they either preceded this major engagement, like Lexington and Concord, which were skirmishes marking the start of armed conflict, or came later in the war, such as the Battle of Saratoga, which was a turning point for American alliances but not the initial demonstration of resilience against a regular army.