In July 1769, Whatcoat became a minister, quickly earning a strong reputation as a problem-solver. John Wesley and Thomas Coke ordained him an Elder in 1784, then Wesley sent Whatcoat and Coke to the United States as missionaries.
Whatcoat became influential among the Methodists in America, known as an effective preacher. His contemporaries attributed his strength chiefly to his devotion. In the year 1800 he was elected bishop, joining Coke and Francis Asbury as the leaders of the Methodist Episcopal Church. After several years of infirmity, he died in Dover, Delaware from dysentery.