For 18 months British research outpaced the American but by mid-1942, it became apparent that the industrial effort required was beyond Britain's already stretched wartime economy. In September 1942, General Leslie Groves was appointed to lead the U.S. project which became known as the Manhattan Project. Two of his first acts were to obtain authorization to assign the highest priority AAA rating on necessary procurements, and to order the purchase of all 1,250 tons of the Shinkolobwe ore. The Tube Alloys project was quickly overtaken by the U.S. effort and after Roosevelt and Churchill signed the Quebec Agreement in 1943, it was relocated and amalgamated into the Manhattan Project.