Complex sentence: He became assistant to Rev. Joseph Lathrop at the West Springfield, Massachusetts, Congregational church in 1819, and the following year, when Lathrop died after sixty years as pastor there, Sprague became senior minister and served there nine more years.
Split into simpler sentences: He became assistant to Rev. Joseph Lathrop at the West Springfield, Massachusetts, Congregational church in 1819. The following year, when Lathrop died after sixty years as pastor there, Sprague became senior minister and served there nine more years.