When Justinian Burch Jr was born on 1 July 1709, in Charles, Maryland, United States, his father, Justinian Burch, was 29 and his mother, Susanna Davis, was 19. He married Ann Dyson about 1723, in Prince George's, Maryland, United States. They were the parents of at least 4 sons and 5 daughters. In 1760, at the age of 51, his occupation is listed as coroner. He died on 10 September 1767, in his hometown, at the age of 58, and was buried in Newport, Charles, Maryland, United States.