James Iverson Boswell was born in Philadelphia on November 3, 1837. He attended the central high school in that city and enrolled at Genesee College in New York in 1856. A year later, Boswell enrolled at Dickinson College in Carlisle, Pennsylvania as a junior. In the year he was at the College, he was elected to the Belles Lettres Society. Boswell graduated with his class in the early summer of 1858.
Boswell then attended the Union Theological Seminary in New York City in 1861 and was later ordained as a Methodist minister. As a member of the Newark Conference, he had a long career as pastor at a string of New Jersey churches located in the following towns: Westfield, Palisade, Mount Hermon, Somerville, Elizabeth (Fulton Street), Newark (Trinity), Newtown, Montclair, Paterson (Cross Street), Jersey City (West Side Avenue), Nyack, Madison, South Orange, Englewood, and Verona. Boswell retired from this particularly mobile ministry of more than four decades in 1903.
In May 1863, Boswell married Cynthia Copeland. James Iverson Boswell died in Ocean Grove, New Jersey on November 30, 1926. He was three weeks past his eighty-ninth birthday. Lease married Catherine A. Bair of Madisonburg, Pennsylvania in June 1862, and the couple had four children. In January 1919, John Henry Lease died of pneumonia in Ohio. He was eighty-six years old.