When Granville Riley Rexroat was born on 11 October 1839, in Russell, Kentucky, United States, his father, George Peter Rexroat, was 37 and his mother, Morna Matilda Hopper, was 34. He married Mary Ann Baldock in 1865, in Des Moines, Polk, Iowa, United States. They were the parents of at least 5 sons and 8 daughters. He lived in Scotland Township, McDonough, Illinois, United States for about 40 years. He died in March 1906, in Macomb, McDonough, Illinois, United States, at the age of 66, and was buried in Macomb, McDonough, Illinois, United States.