On November 3, four days after being promoted to captain, Chiles participated in an advance near Le Champy Bas as part of the Meuse-Argonne Offensive.

In command of a battalion, he oversaw an attack against a large German force, leading his men through a waist-deep stream despite intense machine gun fire.

Wounded during the water crossing, Chiles continued to crawl after his troops after reaching the stream bank.

[1][3] For these actions, he received the Distinguished Service Cross; the award was upgraded to the Medal of Honor the next year.

Citation: When his battalion, of which he had just taken command, was halted by machinegun fire from the front and left flank, he picked up the rifle of a dead soldier and, calling on his men to follow led the advance across a stream, waist deep, in the face of the machinegun fire.