Getting the U.S. ready for a war on another continent was no small task and took the full power of the government to accomplish.
The U.S. began taking small steps towards preparation as early as 1915 when they created the Federal Committee on Industrial Preparedness, which went around inspecting the army and navy. Materials that were designated as imperative for the war effort were regulated under the National Defense Act of 1916. A national defense council was also formed consisting of high-ranking secretaries and began to assess war assets and the overall preparadness of the armed forces and national defense.
There was also a lot of confusion early on when trying to mobilize the home front to support the war effort. Almost a million new government employees were hired to help. The Food Administration, which was overseen by Herbert Hoover, help ration food so it could be sent oversees. The Committee on Public Information meanwhile helped produce pro-war speeches, posters, and even helped repress anti-war sentiment.
While all this was going on, the army was being expanded and trained. A national draft was instituted under the Selective Service Act, and 2.8 million men drafted into the service. Troops began arriving in France as early as 1918, and their arrival helped to tilt the war in the allies favor. The commander of what became known as the American Expeditionary Force, John Pershing, refused to allow his units to be broken up amongst the forces of Britain and France as simple reinforcements. Instead, he had his men fight as a truly American unit where event their tactics set them apart. They still used frontal assaults despite the staggering losses from earlier in the war.