The primary reason many enslaved people served with the British Army during the Revolutionary War was that they wanted the freedom Britain promised for their service. The British offered enslaved individuals the chance to escape bondage and gain their freedom in exchange for military service, which appealed to many who sought liberation from enslavement.
While some enslaved individuals may have been coerced or forced to serve by their enslavers, the overarching factor driving their enlistment was the hope of gaining freedom through military service.