John Merrill died on November 29, 1991 in Columbus, Ohio as a result of complications following a leg amputation made necessary by extreme peripheral vascular disease. He had been incapacitated by this condition for a number of years.
Merrill was born on May 10, 1902 in Parsonsfield, Maine. He received a Master's degree in Greek from Boston University in 1923, a Master's degree in mathematics at Case Institute of Technology in 1927. He then earned a Master's degree in mathematics at Princeton University in 1929, followed by a Ph.D. in astronomy in 1931.