Explain how some Americans were involved in the war even before the United States declared war on Germany.

In 1917, Germany, determined to win its war of attrition against the Allies, announced the resumption of unrestricted warfare in war-zone waters. Three days later, the United States broke diplomatic relations with Germany, and just hours after that the American liner Housatonic was sunk by a German U-boat.

They showed the country that integration could be successful.