Phoebe Palmer Knapp was born in New York City. The daughter of Walter C. Palmer, a well-known Methodist evangelist of that day, Phoebe, at 16, married Joseph F. Knapp, founder of the Metropolitan Life Insurance Company. Both were members of John Street Methodist Church of New York City, whose membership also included blind hymnwriter Fanny Crosby. Phoebe Palmer Knapp published more than 500 hymn tunes, but her most famous work is the tune for Fanny Crosby's beloved hymn "Blessed Assurance."