The guiding star of General Pershing in France was that the Americans were to form a separate Army and operate as a cohesive unit. An Allied Supreme War Council was held on May 1-2, 1918. The discussions were often contentious with Pershing resisting the idea that American units should be amalgamated with French and British units. Finally Pershing conceded with the following agreement which allowed temporary service by American units then in France with the British and French armies:
It is the opinion of the Supreme War Council that, in order to carry the war to a successful conclusion, an American Army should be formed as early as possible under its own commander and under its own flag.
In order to meet the present emergency it is agreed that American troops should be brought to France as rapidly as Allied transportation facilities will permit, and that, as far as consistent with the necessity of building up an American Army, preference will be given to infantry and machine-gun units for training and service with French and British Armies; with the understanding that such infantry and machine-gun units are to be withdrawn and united with its own artillery and auxiliary troops into divisions and corps at the direction of the American Commander-in-Chief after consultation with the Commander-in-Chief of the Allied Armies in France.
Subparagraph A. It is also agreed that during the month of May preference should be given to the transportation of infantry and machine-gun units of six divisions, and that any excess tonnage shall be devoted to bringing over such other troops as may be determined by the American Commander-in-Chief.
Subparagraph B. It is further agreed that this program shall be continued during the month of June upon condition that the British Government shall furnish transportation for a minimum of 130,000 men in May and 150,000 men in June, with the understanding that the first six divisions of infantry shall go to the British for training and service, and that troops sent over in June shall be allocated for training and service as the American Commander-in-Chief may determine.
Subparagraph C. It is also further agreed that if the British Government shall transport an excess of 150,000 men in June that such excess shall be infantry and machine-gun units, and that early in June there shall be a new review of the situation to determine further action.
In hindsight the agreement seems sensible. American units would gain some combat experience with the British and the French on a temporary basis, with an American army formed as soon as sufficient troops had been shipped to France.