William Lafayette Plumb was born on 16. May. 1875 at Richfield, Sevier County, Utah. He was the son of
John Merlin Plumb and
Mary Ann Clifford. William Lafayette Plumb married
Mary Elsie Riggs, daughter of
William Thomas Riggs and
Clarissa Ann Millett, on 29. Mar. 1900 at Saint David, Cochise County, Arizona.
William Lafayette Plumb and
Mary Elsie Riggs appeared on the census of 18. Apr. 1910 at with her mother, Mesa, Maricopa County, Arizona; 4 children, 3 living. William Lafayette Plumb was shown in the census on 18. Apr. 1910 as a teamster, road working.

William Lafayette Plumb was shown in the census on 27. Jan. 1920 as a farmer.
William Lafayette Plumb and
Mary Elsie Riggs appeared on the census of 27. Jan. 1920 at East Chandler Precinct, Maricopa County, Arizona. William Lafayette Plumb was shown in the census on 15. Apr. 1930 as a foreman, farm.
William Lafayette Plumb and
Mary Elsie Riggs appeared on the census of 15. Apr. 1930 at East Chandler Precinct, Maricopa County, Arizona. William Lafayette Plumb died on 7. Jun. 1930 at Chandler, Maricopa County, Arizona, at age 55.