The United States was initially determined to remain neutral as war erupted across Europe. However, pressure mounted as German U-boats attacked and sank ships carrying . citizens and then attempted to persuade Mexico to attack the United States. On April 6, 1917, the . joined WWI and soon held the first of three draft registrations in which more than 24 million . men would register for the draft.
The United States had more than million service members serving worldwide during WWI. More than 50,000 American lives were lost during battle, with some 200,000 non-mortal woundings.