Today in WW II: 13 Jun 1940 Paris, France declared an open city as German Army closes in.  More 
13 Jun 1942 US Government establishes the Office of War Information [OWI] to promote favorable news about the war, best known for their series of memorable and effective posters.
13 Jun 1942 US government establishes the Office of Strategic Services [OSS] by Executive Order 9182.
Visit the Olive-Drab.com World War II Timeline for day-by-day events 1939-1945! See also WW2 Books.

Chart of Military Vehicle Ammunition Trailers

2d Infantry Division M5 high-speed artillery tractor towing an M10 ammunition trailer, near Les Moulins, Omaha Beach West Exit D-3, Normandy, France, 7 June 1944
2d Infantry Division M5 high-speed artillery tractor towing an M10 ammunition trailer, near Les Moulins, Omaha Beach West Exit D-3, Normandy, France, 7 June 1944.

Military vehicle trailers for ammunition...

Vehicle Description Photo Link
M-10 M-10 Trailer, Ammunition, 2-wheel (G-660)  
M-21 M-21 Trailer, Ammunition, 4-ton, 2-wheel (G-213)  
M-23 M-23 Trailer, Ammunition, 8-Ton, 4-wheel (G-216)  
M-332 M-332 Trailer, 1 1/2 ton, Ammunition M-332 Trailer, 1 1/2 ton, Ammunition
M-989 M-989 Heavy Expanded Mobility Ammunition Trailer (HEMAT) 11-Ton