When William Elsworth Mayhew was born on 22 February 1861, in Lower Township, Cape May, New Jersey, United States, his father, Elam Mayhew, was 46 and his mother, Hannah Ackley, was 45. He married Christiana W Trimnell on 6 September 1885, in Plainville, Franklin Township, Gloucester, New Jersey, United States. They were the parents of at least 3 sons and 5 daughters. He lived in Woodbury, Gloucester, New Jersey, United States in 1935 and Clayton, Gloucester, New Jersey, United States in 1940. He died on 24 April 1949, in Atlantic City, Atlantic, New Jersey, United States, at the age of 88, and was buried in Siloam Cemetery, Vineland, Cumberland, New Jersey, United States.