Flatbush played a key role in the American Revolution. Flatbush was where significant skirmishes and battles of the Battle of Long Island took place. As Kings County was settled largely by the Dutch, and as the Dutch were prominent in the slave trade, the area was somewhat sympathetic to the British side of the American Revolutionary War at the beginning of the conflict. Kings County at the time had the highest concentration of slaves north of the Mason–Dixon line – according to the first federal census in 1790, one-third of the total population for the county were slaves. When a Loyalist Governor of Virginia supported freedom for slaves who supported and fought on the British side, landowners in Brooklyn were concerned that a full conflict between the Colonies and the British would result in loss of their critical source of labor. Loyalist residents of Flatbush included David Mathews, Mayor of New York City, who lived at what is now the intersection of Flatbush and Parkside avenues. Flatbush residents maintained their loyalist sympathies: the King's Arms, for example, appeared in the town's inn for a half-century after the conclusion of the conflict.