| Air Mail Service Began: | August 7, 1920 |
| Air Mail Service Ended: | February 9, 1921 |
| Assignment: | College Park, Maryland |
| August 24, 1920 – Chicago, Illinois | |
| September 9, 1920 – Cleveland, Ohio | |
| October 16, 1920 – Minneapolis, Minnesota |
- Courtesy of the Air Mail Pioneers
William M. Carroll died in the same airplane crash that took the life of Hiram H. Rowe and Robert B. Hill. He was buried at Minneapolis, Minnesota.
