[edited with more information -- a source came through]

Well I don't know what the deleted comment was, but I can tell you some basics. The 455th AAA (Anti-Aircraft Artillery) was a unit responsible for defending advancing US troops from enemy air attack. They were nicknamed the "RABBS" because they had a rabbit symbol. The unit was formed in Sep. 1942 and trained at Fort Benning, GA and Camp Stewart, GA. They were stationed at Norfolk, UK, and it seems that at least some of them landed at Normandy on D-Day at Utah Beach, but I can't figure out which parts exactly. Others went to France in July of 1944 (a month after D-Day) as part of "Operation Cobra" and were with Patton's 3rd Army. At least some of the men of the 455th fought in the Battle of the Bulge as replacement soldiers in other units. Here is an example. The 455th was one in a large number of other similar anti-aircraft units. I'm counting at least 13, but not all of them were mobile like the 455th.

From what your father says, your grandfather was, I'm assuming, a second lieutenant and second in command of four gun crews of 15 men (plus some more at HQ) and 2 mobile guns each, an anti-aircraft and a quad .50 cal. There were two of these units in the first platoon, and your grandfather was in the second of the two, or "B" group. Your father says that "B" group was involved in a lot of action and shot down a lot of German aircraft.

In general, your grandfather probably did not shoot the guns very often, if at all. His boss told him orders, and he in turn told orders to the men under him. The unit probably moved around quite a bit, though I can't find a complete record of their journey. In general, they went from Normandy, through France, and into Germany. The guns were mobile, and they moved with the advancing allied forces whenever possible. Once the allies had set up forward air bases in Europe in preparation for the push into Germany, some of the AAA were stationed more permanently at them for protection. I can't find out if the 455th were defending airfields, though. There is not very much information available in my usual hunting spots on the 455th, unfortunately.

AAA or Triple-A is Anti-Aircraft Artillery. In the US Army from 1943, Anti-Aircraft Battalions were classified as either Gun (equipped with large 90mm guns capable of engaging aircraft at high altitude) or Automatic Weapon (AW) (equipped with 37mm or 40mm guns and .50 caliber machine guns for short range point defence). AW Battalions could be Self-Propelled (SP), with the guns mounted on and fired from half-tracks, or Mobile (M), with the guns towed on trailers. The 455th were a mobile automatic weapon battalion, typically referred to as e.g. 455th AAA AW or 455th AAA AW Bn (M). A Battalion was organised into four firing batteries, A through D. A Table of Organization and Equipment (TO&E) for an Antiaircraft Artillery Automatic Weapons Battalion, Mobile from 1944 is [available online] (http://www.militaryresearch.org/44-25%2022Apr44.pdf), if you'd like to see a list of the personnel and equipment for a typical battalion.

An excellent source of information about AAA is the US Army [Air Defense Artillery Online] (http://sill-www.army.mil/ada-online/) site; it has archives of a number of publications going back over the years. The [1994 Air Defense Artillery Yearbook] (http://sill-www.army.mil/ada-online/special-publications/_docs/1994/1994.pdf), for example, has an article about the history of Triple-A and a WWII dispatch from correspondent Ernie Pyle describing life in a gun battery. Specifically for the 455th, they are mentioned in the [Jan-Feb 1946 issue of the Coast Artillery Journal] (http://sill-www.army.mil/ada-online/coast-artillery-journal/_docs/1946/1-2/Jan-Feb%201946.pdf) (page 18 has an account of Staff Sergeant James R. Brown engaging enemy fighters from his truck, page 84 says that the battalion published a newspaper, The Rabbit Leaf). Most pertinent is probably the article "Antiaircraft at Avranches" starting on page 47 of the [Jan-Feb 1950 issue of the Antiaircraft Journal] (http://sill-www.army.mil/ada-online/antiaircraft-journal/_docs/1950/1-2/Jan-Feb%201950%20Screen.pdf). The map on the first page pinpoints the location of your grandfather's platoon at the time (the rectangle with 'A' in the middle, '1B' on the left and '455' on the right, representing 1st Platoon, B Battery, 455th Battalion). They are also mentioned defending against strafing attacks on the 1st August: "East of Sartilly the 455th AAA AW Bn(M) accounted for two Cat I's with M51 fire". (Cat I is Category I, a definitely destroyed aircraft; Cat II is probably destroyed, Cat III is damaged. The [M51] (http://www.lonesentry.com/blog/m51-multiple-machine-gun-carriage.html) was, as your father's message says, a quadruple .50 caliber machine gun, also known as "The Meat Chopper" for the volume of fire it was capable of.)

There is a website dedicated to the 455th, http://www.455thaaa.ukgo.com/ , with some photographs from reunions etc., but the layout is a little idiosyncratic and the guestbook links don't seem to be working for me, but it might give some further leads. The 455th's unit history seems to be [held at the Dwight D. Eisenhower Library in Kansas] (https://www.eisenhower.archives.gov/research/finding_aids/pdf/US_Army_Unit_Records_Index.pdf).

Where did it happen ? Europe, but where exactly ? And when ? How long did your Grandpa spend in his unit ?

Many details on guns, not much about circonstances, men, ... I guess bloody stories... I'm french and im very Grateful to those who fought and won during WW2.

Each Antiaircraft Automatic Weapons Battalion, Mobile had 36 officers and 803 enlisted men per TO&E 44-25 dated 22 April 1944. A battalion consisted of

• A Headquarters and Headquarters Battery (TO&E 44-26) of 9 officers and 89 enlisted men. The battalion was commanded by a lieutenant colonel.

• Four Antiaircraft Automatic Weapons Batteries, Mobile (TO&E 44-27) each of 6 officers and 164 enlisted men, commanded by a captain. In artillery speak, a "battery" is equivalent to a company. Each battery had two platoons; each platoon had four firing sections. There was one M1 40 mm Automatic Gun (with a crew of 5; a gunner and 4 cannoneers) and one M51 Multiple Machine Gun Carriage (with a crew of three machine gunners) per section, for a total of 8 of each weapon per battery; there were a grand total of 32 of each type of weapon in the battalion. The guns were towed by 2 1/2-ton trucks. Your grandfather, per the TO&E, was a second lieutenant, and the executive officer (assistant to the platoon commander) of a platoon, and was issued a carbine for self-defense. He would perform various administrative functions in the platoon, and would become the acting platoon leader if his superior was incapacitated for any reason. The HQ section had a 2 1/2-ton truck with a 1-ton cargo trailer and a jeep, along with 15 radios of various types (9 EE-8 field phones, 5 SCR-593s, and an SCR-543) and a BD-71 switchboard to perform its administrative function. One member of the platoon armed with an M1 rifle was designated to carry an M7 grenade launcher, and there were two .50 caliber machine guns for defense. The HQ section of an antiaircraft automatic weapons platoon was as follows:

Men:

c: armed with carbine, cal. 30

s: armed with gun, submachine, cal. .45

Equipment and Weapons:

• An attached Medical Detachment (TO&E 44-25) of 3 officers and 20 enlisted men to provide for the minor medical needs of the battalion.

More information about the men and weapons in these units can be seen by reading the linked TO&Es. The full site for more of these here.

Antiaircraft Artillery Automatic Weapons Battalions, Mobile were usually assigned to infantry divisions or field army or corps headquarters to protect their rear areas from marauding enemy aircraft. In contrast, the "self-propelled" type of these battalions (equipped with 32 M15 or M15A1 (2 .50 caliber machine guns and a 37 mm cannon) and 32 M16 (4 .50 caliber machine guns) halftracks) usually went to armored divisions.

Occasionally, expecially towards the end of the war when enemy aircraft could not be found, the battalions were used as direct-fire weapons against stubborn fortified positions or enemy infantry. In Italy, several battalions were actually formed into a provisional infantry regiment (473rd; the "Flakfeet") due to the lack of enemy aircraft.

From what I can gather (their official website is a personal site dedicated to a member of the battalion killed in action in Germany and is now offline) the 455th was activated at Fort Stewart, Georgia on September 1, 1942 and first assigned to the 10th Armored Division. It was detached from the 10th Armored Division when that unit went on maneuvers and moved to England in September of 1943, providing protection for two 8th Air Force airfields. The 455th moved into Normandy over Utah Beach in July 1944 and was assigned to VIII Corps (First US Army) for the advance into the Brittany Peninsula and then, after that, the newly arrived XX Corps (Third US Army) to provide protection for rear areas of Patton's armored and infantry divisions. It advanced through France, Belgium, Luxembourg, the Netherlands, and deep into Germany. During their time with Third Army, they achieved the second-highest score of all battalions in that Army, shooting down 80 German aircraft and probably destroying 31. Some interesting posts drawn from the now-defunct website can be read here

Hello there! As your question is related to looking for identification/information regarding military personnel, our Guide on Military Identification may be of use to you. It provides a number of different resources, including how to request service records from a number of national agencies around the world, as well as graphical aids to assist in deciphering rank, unit, and other forms of badges or insignia. While the users here may still be able to lend you more assistance, hopefully this will provide a good place to start!