When Alexander Fairchild was born on 2 July 1704, in Bridgeport, Fairfield, Connecticut, United States, his father, Alexander Fairchild, was 23 and his mother, Deborah Jackson, was 22. He married Mary Mallory on 24 February 1727, in Fairfield, Connecticut, United States. They were the parents of at least 5 sons and 6 daughters. He died in 1751, in Fairfield, Fairfield, Connecticut, United States, at the age of 47, and was buried in New Fairfield, Fairfield, Connecticut, United States.