When William John Trego was born on 23 September 1901, in McPherson, Nebraska, United States, his father, Nathan Evan Trego, was 34 and his mother, Sarah May Wilson, was 23. He married Hazel A Cherry on 26 May 1928, in Nebraska, United States. They were the parents of at least 1 son. He lived in Garden, Nebraska, United States in 1935 and Whitewater Election Precinct, McPherson, Nebraska, United States in 1940. He died on 20 June 1976, in North Platte, Lincoln, Nebraska, United States, at the age of 74, and was buried in North Platte Cemetery, Lincoln, Nebraska Territory, United States.