"Pvt. C. Erwin Heard was born August 8, 1894, at McKinney, and received his education at the public schools there. Son of Mr. and MRs. C. P. Heard of McKinney. He volunteered in the air service April 4, 1918, and was assigned to 868th Aero Squadron at Love Field, Dallas. He served as a mechanic and was awaiting overseas orders at Love Field when the armistice was signed."
Colonel John McCrae, “Pvt. C. Erwin Heard,” McKinney Public Library Digital History, accessed September 28, 2023, https://mckinneylibrary.omeka.net/items/show/527.