Prior to the outbreak of World War II both the British and French Governments had been investigating the possibilities of purchasing armaments from the North American Continent. A French Air Mission led by M. Jean Monnet in 1938/39, had placed important contracts in the USA for complete aircraft, and also aeroengines. The British Air Ministry also sent a Mission to the USA and Canada in 1938, headed by Sir Henry Self. Apart from making special purchases of aircraft in the USA the Mission also explored the possibilities of increasing the potential of Canadian aircraft production, and the manufacture of British types under licence.
Discussions about the opening of a purchasing agency in North America had been going on since the beginning of 1939 and in August of that year Lord Riverdale visited Washington and Ottawa. On his return he recommended the setting up of a Purchasing Mission in Washington.
In the early days of the Ministry of Supply a British Supply Board was set up in Canada to purchase munitions from Canadian sources. In November 1939 an offshoot of this became the British Purchasing Commission in Washington, responsible for purchases from the USA.
In the same month (November 1939) the "British Supply Board in Canada and the United States" was established in)Ottawa with Col J H M Greenly as Controller General and Chairman. The British Supply Board was not a direct purchasing agency, its functions were to co-ordinate purchasing in Canada and the United States. Orders for Canadian material were to be placed by the British Supply Board through the Canadian Government's own Supply Board, whilst American orders were to be dealt with by the newly-formed British Purchasing Commission, headed by Mr A Purvis in New York. The formation of the new organisation was announced on the 7th November 1939, just 3 days after the repeal of the United States arms embargo under the revised Neutrality Act.
In January 1940 the Anglo-French Purchasing Board was set up in New York with A Purvis and Bloch-Laine as Chairman and Vice-Chairman respectively. When it became apparent that the fall of France was imminent, the Purvis/ Bloche-Laine association, backed by the authority of the Anglo-French London Committee, assigned existing French contracts over to the British Government. After the collapse of France, the British Supply Board in Canada was wound and United Kingdom orders were placed direct on the Canadian Department of Munitions and Supply in Ottawa.
Increased demand for the production of aircraft and aero-engines in the United States led to the formation of the British Air Commission under the Director Generalship of Sir Henry Self. Functioning first of all within the framework of the British Purchasing Commission it became established as a separate Mission in November 1940, responsible to its parent body, the Ministry of Aircraft Production. About this time other organisations were emerging from within the British Purchasing Commission to become established Missions in their own right, each representing their parent UK Ministry.
On the formation of the Ministry of Aircraft Production in 1940 the minister sent a personal representative to North America to make arrangements for the supply of American and Canadian aircraft and equipment. In August 1940 a special Technical Mission, headed by Professor Tizard, went to America to exchange scientific information, especially that relating to aviation.
In October 1940 the Ministry of Aircraft Production set up a British Air Commission in Washington on a formal basis to be the link between the ministry and North American departments and suppliers. In July 1942 the British Purchasing Commission became the British Ministry of Supply Mission. Meanwhile, the British Supply Board had been dissolved in 1940, being replaced by a number of smaller technical missions. A British Ministry of Supply Mission to Canada was set up in December 1942.
In January 1941, the British Supply Council in North America came into being. The Council consisted of the heads of the various Missions, who met at regular intervals to co-ordinate policy and discuss common subjects; a Civil Secretariat was also installed to work in conjunction with the Council. The Chairman communicated directly with the North American Supply Committee to the Home Cabinet. In December 1942, the Prime Minister appointed Col J J Llewellin (the former Minister of Aircraft Production), as Resident Minister for Supply in Washington. He was succeeded in 1943 by Sir Ben Smith, who remained in the post until the war ended.
After the United States entry into the war it became apparent that the procurement organisation of both the United States and the United Kingdom would need to be closely integrated, and to meet this requirement the first of the Combined Boards came into being early in 1942.
In July of the same year the British Purchasing Commission was re-named as the British Ministry of Supply Mission and later in the year the British Army Staff was linked with this organisation.
The British Air Commission was the concern of a senior official of the ministry, known at first as the Director of Canadian and American Purchases, in 1941 as the Controller of North American supplies, in 1942 as the Controller of North American Supplies and Repairs, and from 1943 as the Controller of Repairs, Equipment and Overseas Supplies. In 1945 the Commission changed its name to the British Supply and Air Commission and in 1946 it was wound up along with the British Ministry of Supply Mission.
By the summer of 1943 the North American Supply Missions and associated departments had grown into a large complete organisation resembling an "overseas Whitehall".