Helmet Insignias of the 80th Division

Source:
Second full paragraph on page 130 of History of the Eightieth Division, A.E.F., authored by Russell Stultz, and edited, enhanced and published by Dr. Anthony in 2004:
Previously announced, the distinctive symbols of the various units of the Division were declared official on April 30th. For the four Infantry regiments, in their order beginning with the 317th Infantry, they were a diamond, square, circle, and half-circle; the symbol of each unit's Headquarters Company was colored red. white and blue, that of the Supply Company red and white and that of the Machine Gun Company red and blue; the battalion symbols were colored red, white,and blue, in numerical order. The three Machine Gun Battalions were identified with a shield - blue and white, red and white, and red and blue, in order, beginning with the 313M. Other units of the command were assigned equally distinctive symbols, thereby enabling property and individuals to be immediately identified by the markings required on the packing cases, wagons, helmets, and other property articles.

Mr. Stultz was the official historian for the 80th Division in WW I, and spent years compiling data for his manuscript. Stultz did not specifically identify lesser units (MST, Field Signal Bn, etc.) and I have seen a few other markings that obviously were utilized by these units.

Infantry Units

The 317th Infantry included men from the Piedmont and Western Virginia areas, the 318th Infantry was made up mostly of men from the Shenandoah Valley and Tidewater areas; the 313th Machine Gun Battalion were mostly men from the Erie area. These units comprised the 159th Brigade.        

The 319th Infantry included men from Allegheny County and from that area north to Erie, and some from Eastern Ohio. The 320th Infantry were mostly men from Pittsburgh; the 315th Machine Gun Battalion were men from Pittsburgh and Erie. These units combined to create th e 160th Brigade.

Artillery Units

The 313th , 314th and 315th Field Artillery units were comprised of men almost exclusively from the State of West Virginia, and were the 155th Field Artillery Brigade.

All Artillery Units wear the "Gun Sight" on their Helmets.It referenced the 313th and 314th with two blocks at approximately 45 degrees and 270 degrees .The 315th was 155 mm and their gunsight emblem was a variation of this emblem.It contained the infantry colors in the four quadrants (blue).In the center, there was a star, and the battery letter was in the center of the star.

Divisional Troops

Serving with the Division were the 314th Machine Gun Battalion, men from the Tidewater area, as well as the 305th Engineers, men from an area east and north of Pittsburgh; the 305th Trains (Ammunition, Motor Supply and Sanitary) were men from Western PA, WV and VA.