[2][3] Among his classmates included several general officers of the future, such as Charles Gerhardt, Ulysses G. McAlexander, Ernest Hinds, Nathaniel Fish McClure, William Weigel, Charles S. Farnsworth, James Theodore Dean, Mark L. Hersey, Herman Hall, Frank Herman Albright, Marcus Daniel Cronin, George Owen Squier, Thomas Grafton Hanson, Michael Joseph Lenihan, Alexander Lucian Dade and Edmund Wittenmyer.

After serving with the Rhode Island National Guard from 1911 to 1915 as an instructor and inspector, Gatchell commanded Fort Williams in Maine, along with Portland's defenses, between 1915 and January 1918.

[5][3] Gatchell was promoted to the rank of brigadier general on August 17, 1917, over four months after the American entry into World War I.

He participated in World War I in France as part of the American Expeditionary Forces (AEF), commanding the 31st Heavy Artillery Brigade from March 1918.

[5][3] Congress restored Gatchell's brigadier general rank in June 1930, and he died in San Diego on February 4, 1939.