Years before the 341st Bombardment Group existed, the two squadrons which would be the core of the Group had experienced combat, both in the first World War and already in the second, first as Heavy Bombardment units of the 7th Bombardment Group, then as Medium Bombardment units again assigned to the 7th.

The nascent 341st Group would benefit from the B-25 operations experience of several of the now famous bombing of several targets on Japan's main island, the "Tokyo Raiders" who remained in CBI as originally planned. Also among the personnel brought together to form the 341st were men who had delivered light bombers to the Chinese Air Force.

Originally established and organized as First Army Observation Group on 6 Sep 1918. Demobilized in Apr 1919; redesignated 7 Group (Observation) in Mar 1921 and inactivated on 30 Aug 1921. The unit was redesignated: 7 Observation Group on 25 Jan 1923, 7 Bombardment Group on 24 March and reactivated on 1 Jun 1928. Redesignated as 7th Bombardment Group (Heavy) on 6 Dec 1939.

Four squadrons were assigned to 7th Bomb Group during the months leading up to the start of World War II; 9th Bombardment Squadron (Heavy), 11th Bombardment Squadron (Heavy) [detached 26 Apr-28 May 1942], 14th Bombardment Squadron (Heavy) (detached 2 Dec 1941-May 1942; not manned May 1942-6 Jan 1946). The fourth, 22nd Bombardment Squadron (Heavy) [detached 26 Apr-28 May 1942]. In addition, 88th Reconnaissance Squadron (Heavy) was attached until it was fully assigned on 25 Feb 1942. They operated the B-18 bomber and the A-17 attack aircraft. After gathering personnel and equipment at Hamilton Field and conducting training the units then re-equipped with the B-17 Flying Fortress, moved on to Fort Douglas, Utah on 7 September 1940, and later to Salt Lake City, Utah in June 1941. The 9th and 11th Squadrons performed rescue and patrol duties from Fort Douglas, UT, c. 21 Jun - 13 Nov 41.

In November 1941 the 7th Bombardment Group prepared for reassignment to the Philippines. The ground echelons sailed from San Francisco on 21 November with the air echelons expected to delay, timing their arrival to the ground echelon's arrival in the Philippines. Before that could occur the Japanese attacked Pearl Harbor on December 7th, and shortly thereafter began the campaign against the Philippines, which caused the ship bearing the ground echelon of 7th Bombardment Group to be diverted to Australia.

First of the 7th Bomb Group's air echelon to depart for the Philippines was a flight from the 88th Reconnaissance Squadron. The seven planes reached Hawaii in the middle of the Japanese attack on Pearl Harbor. The air echelons of the 11th and 22nd were held in the USA to conduct anti-submarine patrols from Muroc, California from 8 to 12 December 1941 before moving on out into the Pacific Theater. Assigned detached duty to U.S. Navy at Brisbane, Australia, 22 Dec 41, the squadrons flew combat while operating from Hickam Field, HI, 18 Dec 41 - 5 Jan 42, before the air echelons of the 11th and 22nd moved to Jogjakarta, Java, briefly operating from Singarosi, Java, 13 - 19 Jan 42. By the end of the month, the ground echelon rejoined the air echelon. The Squadrons moved on to the Fiji Islands on 14 Feb 42.

Japanese forces attacked the Netherlands East Indies about the same time the air echelons of the 11th and 22nd arrived, beginning a battle that ended in the withdrawal of United States forces in early March. During the unsuccessful defense of the Indies, the main body of the Squadrons flew from Jogjakarta, meanwhile a detachment operated under Navy control from the Fiji Islands and then from Australia.

On/about 4 March 1942 the 11th and 22nd Squadrons withdrew to Melbourne, Australia, where they remained for about a month. In April 1942 all of their equipment and personnel were transferred to 19th Bombardment Group. Then, via official paperwork, the Squadrons were "transferred without personnel" from Australia to the United States and attached to 17th Bombardment Group (Medium) at Columbia AAB, South Carolina.

Soon they would be restaffed, re-equipped, redesignated "Bombardment Squadron (M)" and ordered to China Burm India theater.

The very first Army Air Corps unit to operate the 'Mitchell' was the 17th Bombardment Group, which had been flying the B-18 'Bolo' bombers. The 17th was equipped with North American Aviation's B-25 in early 1941, receiving the B-25A while stationed at McChord Field, Tacoma, Washington. Two months later they received and began operating the "bent wing" B-25B model.

North American Aviation began delivering the very first B-25 'Mitchell' bombers to the Army in 1941. Twenty-one of the aircraft were accepted between February and May. These aircraft were followed by the B-25A, which had armor protection for the crew and self-sealing fuel tanks. After 40 such aircraft had been delivered, the model B-25B was begun. It had rotating, powered upper- and lower-turrets, to replace the waist and tail guns which had been removed. Fourteen of these aircraft had been delivered by August 1941, with 130 'Mitchells' available when the Japanese attacked Pearl Harbor, and 171 by the end of 1941, such was the result of the frenzied U.S. military production begun in early 1940. In January 1942, 119 B-25Bs were delivered before the production switched to the B-25C.

The 17th BG had reached full strength in September 1941, and was embarked on fully task qualifying all its personnel, when several aircraft and crews were sent to Jackson, Mississippi, to participate in the Army's "very large maneuvers." Lt. Ted Lawson's Squadron had returned to March Field, California when war broke out. Almost immediately following the Japanese attack on Pearl Harbor, and the Declaration of War, the Group's 34th, 35th and 95th Bombardment Squadrons began flying their B-25s on antisubmarine patrols from McChord Field, Washington, as well as from Pendleton, Oregon.

Lt. Col. William C. Mills, Commander, 17th Bombardment Group, received orders on February 3rd, 1942, to transfer the Group and the attached 89th Reconnaissance Squadron to Columbia Army Air Base, South Carolina. The men anticipated performing anti-submarine missions along the southeastern coast of the United States and would do so, although not as anticpated.

Almost immediately upon theird arrival at Columbia aircrews of the four squadrons were told volunteers were needed for an extremely dangerous mission, which would be of great value to the war effort and would require the highest degree of skill. The overwhelming response was that every man who learned of the mission had volunteered. Col. James Doolittle, Commanding 'B-25B Special Project', had selected Maj. John A. Hilger, C.O. 89th Recon Sqdn, as his deputy, responsible for idenifying qualified crews and required ground personnel to start a training program stressing very short takeoff runs.

At Hilger's direction the Squadron Commanders drew up rosters for the 24 crews, with approximately an equal number coming from each of the bomb squadrons and the recon squadron. In addition, mechanics, armorers, radio men and ground support personnel were also selected. The crews and support personnel were ordered to Eglin Field, Florida, as rapidly as aircraft were made available to transport them. The major part of the B-25B Special Project arrived at Eglin Field between 27 Feb and 3 Mar 1942.

Sixteen planes and eighty crewmen would be loaded on the deck of USS Hornet (CV-8), transported to a point about 500 miles from Tokyo and launched to perform the first offensive mission of WWII upon the Japanese homeland. After completing their mission the plan was for crews to proceed to China and land at airfields near the coast. Things didn't go quite as planned for "Doolitle's Raiders". (for the rest of the story)

Remaining crews and support personnel of the 17th Bombardment Group at Columbia had been tasked to establish training and orientation programs for incoming personnel, which would prepare them for operating and maintaining B-25s assigned a combat role. Many of whom would rejoin their comrades in India and China before the end of 1942.

-- continued with Build Up of the 341st Bomb Group --