In what way did some enslaved people benefit from the war of 1812?

when the british occupied cumberland island admiral george cockburn declared any enslaved africans on the island free. 1483 enslaved africans joined the british squardron on cumberland island for their freedom. 

Do you have more info about it ? i doubt this is the answer because i don't have all the information but if trouble was brewing in a clinic maybe it was an argument as to which clinic was better or smth of that nature