9th Air Force

86th Infantry Division

19th Infantry Regiment

1st Troop Carrier Command

320th Field Artillery

US Army Distinctive Unit Insignia

A major in the 40th Infantry Division with Division distinctive insignia on his uniform's epaulets.

11th Airborne Division

Seventh Armor Division

511th Infantry Regiment

7th Calvary Regiment

209th Field Artillery

Port of Embarkation

155th Infantry Regiment

101st Airborne

Division

5th Calvary Regiment

16th Cavalry

Recon

11th Infantry Regiment

Left to right: pre-WWII  post and screw back, WWII period pin back,WWII period open clutch pin back,                                        post WWII German Manufacture pin back, Vietnam era clutch back.

505th Parachute Infantry Regiment

The United States Army distinctive unit insignia (DI or DUI), or unit crest, were authorized in the early 1900s  for wear on officers mess uniforms.  The practice eventually expanded to all dress uniforms, officer and enlisted.  During part of WWII (1943-1945) the manufacture of crests was prohibited.  With the end of the war DIs were manufactured by many companies in Britain, Germany, and Italy.  A great article about Distinctive Unit Insignia Dr. Howard G. Lanham can be found here:   Dating Metallic Insignia 

Alaska Command

Army Air Corps

Kiska

Task Force

West Point

Military Academy

Western Pacific Forces

5th Air Force

South Atlantic Military District

My Cool Old Stuff