Answer:
Summer 1916:
President Woodrow Wilson is re-elected on a campaign of neutrality in World War I.
January 1917:
The German government announces a policy of unrestricted submarine warfare.
The US government begins to prepare for potential entry into the war.
March 1917:
The United States declares war on Germany.
April 1917:
American troops begin to arrive in Europe to fight in the war.
May 1917:
The first major American offensive of the war takes place in the Battle of Cantigny.