During World War 1, the United States was

On the British side fighting against the Germans and Later on Russia joins the allies.

Explanation: Germany and the others were apart of the Central powers because they were in the center of Europe. Also the United States joined the war because Germany sent a message to Mexico to attack the United States but Mexico declined and told the U. S about it, and after Germany had sunk their ships heading to Britain with some passengers the U. s was furious and decided to join in.