Following the entry of the United States into the Second World War in 1942, U.S. Major General Carl Spaatz travelled to England to make arrangements for the U.S. 8th Army Air Force to transfer its headquarters there. During his visit Spaatz met with Brigadier Crockatt and was briefed on MI9 and its role in aiding downed aircrew to escape and evade back to England. Spaatz was extremely impressed with MI9 and lobbied for a member of British Military Intelligence to travel to the USA to conduct a briefing on MI9 and its duties to the U.S. General Staff.
As a result, Air Vice-Marshal Charles Medhurst, KCB, CB, OBE, MC, in his role as Chief of the Air Staff (Intelligence), travelled to Washington in March 1942 to meet with General George C. Marshall, the U.S. Chief of Staff, and Henry L. Stimson, the Secretary of War, to brief them on the activities of the MI9 organization, its role and its successes in bringing aircrew home from occupied Europe.
In October 1942 the embryonic U.S. Military Intelligence Service X (MIS-X) came into being on paper. Stimson advised Catesby ap C. Jones – Prisoner of War (PW) Branch Commander at Fort Hunt – that he would be forming a second MIS department at Fort Hunt alongside the existing MIS-Y organisation already based there. It would be known as MIS-X.
Upon its formation, MIS-X comprised five sections – interrogation, correspondence, prisoner of war locations, training and briefing, and technical. It was commanded by Colonel Gatesby ap C. Jones, the Prisoner of War (PW) Branch Commander.
He appointed Lt. Col. W Stull Holt to work alongside Crockatt in England to establish guidelines for American aircrew based upon MI9’s experience. With British and American aircrew operating in the same skies over Europe, it was entirely logical for MI9 and MIS-X to work in close harmony and to share knowledge on escape lines and escape and evasion techniques. The two men formed a very close relationship, and the success of MIS-X, under the excellent leadership of Lieutenant Colonel J. Edward Johnston – who also recognised the value of MI9’s experience – was assured.