On May 25, 1738, Pennsylvania and Maryland signed a provisional peace agreement in London to halt the violence of Cresap’s War — a bitter frontier conflict over an unresolved boundary. Maryland frontiersman Thomas Cresap raided Pennsylvania homesteads until his capture, famously insisting from a Philadelphia jail that it was “the prettiest town in Maryland.” The truce held only temporarily; the true border would not be settled until the Mason–Dixon survey decades later.