What Battle showed the British that the colonists would be difficult to defeat?

The Battle of Bunker Hill, fought on June 17, 1775, demonstrated to the British that the American colonists would be a formidable opponent. Despite ultimately losing the battle, the colonists inflicted significant casualties on the British forces, showing their determination and capability in combat. This confrontation highlighted the colonists' willingness to fight for their rights and independence, signaling that the conflict would not be easily won by the British.