Why was the Battle of Bunker Hill considered a moral victory even though the patriots lost the battle?

The Battle of Bunker Hill, fought on June 17, 1775, was considered a moral victory for the patriots despite their tactical loss because it demonstrated their ability to stand up to British forces, inflicting significant casualties on a professional army. The fierce resistance showcased the determination and resolve of the colonial fighters, boosting morale and encouraging more colonists to join the revolutionary cause. Furthermore, it highlighted the potential for a protracted conflict, suggesting that the British could not easily suppress the insurgency. This psychological impact galvanized support for the revolution, signaling that the patriots could challenge British authority.