When Mathias Hillyard was born on 12 December 1790, in Virginia, United States, his father, Amos Hilliard, was 30 and his mother, Susan McFarland, was 29. He married Prudence Frush on 21 February 1815, in Rockbridge, Virginia, United States. They were the parents of at least 8 sons and 2 daughters. He died on 27 March 1858, in Weaver, Randolph, West Virginia, United States, at the age of 67, and was buried in Junior, Barbour, West Virginia, United States.