 In late 1777 , Brant relocated to Fort Niagara at the request of Major John Butler , who wanted to make use of her influence among the Iroquois . At Niagara , Brant worked as an intermediary between the British and the Iroquois , rendering , according to Graymont , " inestimable assistance there as a diplomat and stateswoman " . Meanwhile , in November 1777 Brant 's son Peter Johnson was killed in the Philadelphia campaign while serving in the British 26th Regiment of Foot . 
