Halleck Welles, Jr. entered the military service in Massachusetts. He served in the U.S. Army during World War I as a Captain in the 104th Infantry Regiment, 26th Infantry "Yankee" Division. He died on August 1, 1918 and is now buried in Suresnes American Cemetery, Suresnes, France. He was awarded the Distinguished Service Cross for extraordinary heroism in action while serving with 104th Infantry Regiment, 26th Division, A.E.F., near Bouresches, France, July 20, 1918. Lieutenant Welles was seriously wounded in exposing himself to enemy machine-gun fire in order to locate the source. He nevertheless refused to be evacuated but continued in the advance with his men, inspiring them by his bravery. His name is commemorated on the tablet inside a church in Belleau, France and ranked as a First Lieutenant.