John “Swearing Jack” Waller (1741–1802) was an anti-Baptist lawyer who became a Baptist preacher. An Anglican, Waller spent his early career helping to prosecute Baptists in Virginia. In 1767, however, following a grand jury indictment of an unlicensed Baptist preacher named Lewis Craig, Waller was inspired by Craig’s religious conviction to give up his “wicked” ways and be baptized himself. In 1770, Waller was ordained as a Baptist pastor, and he soon became a widely known preacher, baptizing hundreds of converts before his death in 1802...