Photograph of four unknown World War One soldiers on horseback, all wearing their uniforms.

Photograph of three unknown soldiers standing in front of the barracks in camp; all three are wearing their uniforms and campaign hats.

Portrait of an unknown World War One soldier wearing his uniform.

Portrait of an unidentified World War One soldier standing next to a chair while dressed in his uniform.

Portrait of an unidentified World War One soldier standing in his uniform next to a chair.

Portrait of an unknown World War One soldier sitting in a chair and wearing his uniform.

Portrait of an unknown World War One soldier standing by a table in his U. S. Army uniform.

Portrait of an unknown World War One soldier in his uniform.

Portrait of Joe Back dressed in his World War One uniform.

Portrait of Oscar D. Back standing in his World War One U. S. Navy uniform.

Portrait of three unknown World War One soldiers all wearing their military uniforms. The soldiers on the left and right are sitting in chairs while the one in the middle is sitting on a table.

Portrait of Wayne Back as a World War One soldier in uniform.

Photograph of a group of soldiers in Cameron Park in Waco, Texas. Two of the soldiers can be seen sitting on outdoor parallel bars. The soldiers are positioned in front of a wooded area of the park. Handwritten text on the back identifies the WWI soldiers as Dan Ohern, George Fellers, George Jorgenson and Mirt Andrews .

World War One-era "small box respirator" gas mask, consisting of a canvas or cloth face piece, with inset glass or resin eye lenses, and straps that wrap around the back of the head. The front of the mask has a valve located behind a cloth-covered tube that goes over the mouth and attaches to a small yellow metal box containing activated charcoal (made of peach pits or the pits from other stone fruits). The wearer would have breathed only through the mouth, inhaling air scrubbed clean by the charcoal in the box, and had their nose squeezed shut by a clip inside the mask.