February 1940

The 25th Bombardment Group (Heavy) was activated at Langley Field, Virginia, on February 1, 1940 (General Orders No. 1, Air Base Headquarters, Langley Field, Virginia, January 6, 1940).  The 25th Bombardment Group (Heavy), at the time of its activation, consisted of the 10th, 12th, and 35th Bombardment Squadrons (Heavy).  Major T. J. Koenig assumed command of the 25th Bombardment Group (Heavy)(General Order No. 1, Hq. 25th Bombardment Group. Group, February 1, 1940).  Group Headquarters was set up in vacant Officers Quarters, near the Balloon Hangar, Langley Field, Virginia.  The original personnel were drawn chiefly from the 2nd Bombardment Group (Heavy), a limited number of men being furnished by several other organizations.

October 1940

General Orders No. 1, which activated the Group, designated its permanent location as Puerto Rico, and on October 26, 1940, the entire organization departed from Langley Field for Fort Monroe.  The following day the units embarked aboard the U.S. Army Transport, Hunter Liggett, which, after Stopping at Charleston, SC, to take on the 24th Air Base Personnel, set course for San Juan.

The journey was without incident and the ship docked on October 31, 1940.  On the following day, the men disembarked, boarded a train, and were transported to Borinquen Field, located on the northwestern corner of the island.  The Air Echelon of the Group, consisting of 14 B-18As and two A-17 airplanes, 32 officers, and 44 enlisted men, arrived at Borinquen Field.

Borinquen Field, which was later to become a large permanent base with excellent facilities of all kinds, was undergoing construction in 1940, so much time had to be spent in improving living conditions in general, and in particular, in devising means to combat mosquitoes and sandfleas.

February 1941

The 25th Group held an Organization Day Party near the Borinquen Lighthouse on the occasion of its first. anniversary.  The party, from all reports, was a memorable event.

April 1941

More than one-half of the 25th Bomb Group's personnel were transferred to the 40th Bombardment Group (Medium) when that organization was activated on April 1, 1941.  Soldiers from the Air Corps unassigned and from Base personnel replaced these men.

November 1941

The 25th Bombardment Group's Squadrons were distributed throughout the area, and the Group never again functioned as a unit on a single field.  The Squadrons, except for the 10th and 417th Bombardment Squadrons,  which remained at Borinquen Field, PR., began movement from Borinquen Field to Benedict Field, St.. Croix, in the Virgin Islands, on November 6, 1941.  The Group Headquarters and the 12th Bombardment Squadron remained at Benedict Field, while the 35th Squadron. was sent to Coolidge Field, Antigua, on November 11, 1941.

March 1942

The 417th Bombardment Squadron (Heavy), formerly the 27th Reconnaissance Squadron, was assigned to the 25th Bombardment Group on March 3, 1942, with Station at Borinquen Field, PR.  The 417th had been in the area since November 1939, and was a valuable addition to the Group because of its trained personnel and their knowledge of the Caribbean.

May 1942

The 25th Bombardment Group was assigned B-17 type of aircraft, and designated "Heavy" bombardment when it was activated.  The designation of the 25th Group was altered from "heavy" to "medium" on May 7, 1942, after the original B-17s had been exchanged for B-18 aircraft.

September 1942

Hq. & Hq. Squadron. 25th Bombardment Group, and the Group's medical detachment were disbanded on September 10, 1942.

The 417th Bombardment Squadron was relocated from Borinquen Field, PR, to Vernam Field, Jamaica, September 24, 1942.

October 1942

The 9th Bombardment Group (Heavy), stationed in the Trinidad Sector, was ordered back to the United States in October 1942, and transferred its personnel and equipment to the 25th Bombardment Group (Medium).

The 12th Bombardment Squadron was moved to Dakota Field, Aruba, NWI, from Benedict Field, St.. Croix, on October 10, 1942.

November 1942

The 25th Bombardment Group (Medium) moved its headquarters from Benedict Field, St. Croix, to Edinburgh Air Base, Trinidad, November 1, 1942.

The 10th Bombardment Squadron was moved to Edinburgh Field, Trinidad, from Borinquen Field, PR, with only a few of its original personnel, and its name bestowed upon the personnel of the 1st.Bombardment Squadron of the 9th Bombardment Group (Heavy).

The 35th Bombardment Squadron was relocated from Coolidge Field, Antigua, to Zandrey Field, Surinam, on November 1, 1942, with a detachment located at Atkinson Field, British Guiana, the personnel being obtained from the 99th and 430th Bomb. Squadrons of the 9th Bombardment Group (Heavy).

The 10th and 35th Bombardment Squadrons were under the operational control of the Trinidad Detachment and VI Fighter Command, AATF & VI Fighter Command.  The 417th Bombardment Squadron was controlled directly by AATF & VI Fighter Command (later redesignated Antilles Air Command), and the 12th Bombardment Squadron was attached to the Curacao Detachment, AATF & VI Fighter Command.  The Headquarters 25th Bombardment Group concerned itself with administrative matters, and operated several control rooms from which flying activities were directed.

December 1942

May 1943

The 417th Bombardment Squadron was relocated from Vernam Field, Jamaica, to Losey Field, PR, on May 29, 1943.

June 1943

Hq. 25th Bombardment Group moved from the Naval Operating Base in Port of Spain, Trinidad, BWI, to St.. Clair Cantonment, Port of Prince on June 6, 1943, and back to Edinburgh on June 15, 1943.

August 1943

Hq. 25th Bombardment Group established at Fort Amsterdam, Curacao, NWI, on August 1, 1943, while a detachment of the Headquarters remained at Edinburgh.

October 1943

The 10th Bombardment Squadron was relocated from Edinburgh Field, Trinidad, to Waller Field, Trinidad, October 1, 1943; and the 35th Bombardment Squadron moved from Port of Spain, Trinidad, to Vernam Field, Jamaica, on October 7, 1943

The 59th Bombardment Squadron was assigned to the 25th Bomb. Group on October 11, 1943, and stationed at Beane Field, St.. Lucia.  The 59th was activated at Rio Hato, R. de P., on January 2, 1941.  It was originally a Light Bombardment Squadron and its crews had flown many hundred of hours on anti-submarine patrols, principally in A-20 type aircraft.

Hq. 25th Bombardment Group was transferred from Curacao, NWI, to its original Caribbean base at Borinquen Field, PR, on October 5, 1943, where it was joined by the personnel of the Group's Trinidad Detachment on October 13, 1943.

Hq. 25th Bombardment Group was given full operational and administrative control of its Squadrons on October 11, 1943, and shortly thereafter began an intensive training program with the B-25 series of planes.  The men worked assiduously to bring themselves to the point of efficiency that would enable the organization to function perfectly if it were sent to a combat theater.

November 1943

The 12th Bombardment Squadron was relocated from Dakota Field, Aruba, NWI, to Coolidge Field, Antigua, on November 23, 1943.

December 1943 

January 1944

The 25th Bombardment Group was alerted on January 24, 1944, of a pending unit movement, and placed in a state of readiness.

February 1944

The 35th Bombardment Squadron was relocated from Vernam Field, Jamaica, to Trinidad, on February 7, 1944.

March 1944

The 25th Bombardment Group (Medium) and its units- - the 12th, 35th, 59th, and 417 Bombardment Squadrons (Medium) departed Trinidad on March 24, 1944

April 1944

The 25th Bombardment Group (Heavy) arrived at Alamogordo Army Air Field, NM, in April 1944.

June 1944