John Callaghan died on January 27, 1929, less than three weeks into his term. Isaac Frazier was appointed to fill the vacancy and served the remainder of the term.
Source for Popular Vote data: Arizona Secretary of State. Official Canvass General Election Returns, November 6th, 1928, Arizona Secretary of State (https://azmemory.azlibrary.gov/nodes/view/102412) (accessed 19 Nov 2023)