When Cyrus Foust was born on 28 June 1846, in Fayette, Pennsylvania, United States, his father, John Foust, was 34 and his mother, Elizabeth Chadbourne, was 32. He lived in Saltlick Township, Fayette, Pennsylvania, United States in 1860 and Bullskin Township, Fayette, Pennsylvania, United States in 1880. He died on 28 December 1881, in Fayette, Pennsylvania, United States, at the age of 35, and was buried in Pennsville, Bullskin Township, Fayette, Pennsylvania, United States.