The most successful fighter of the entire war was Rittmeister von Richthofen (1892-1918). He shot down 80 planes, more than any other WWI pilot. He died after being shot down near Amiens. France's René Fonck (1894-1953) was the Allies' most successful fighter pilot, shooting down 75 enemy planes.
To increase the size of the U.S. Army during WWI, Congress passed the Selective Service Act, which was also known as the conscription or draft, in May 1917. By the end of the war, 2.7 million men were drafted. Another 1.3 million volunteered.
While the first military submarine (named the Turtle) was first used by the Continental Army during the American Revolution, submarines only made a large military impact during WWI when Germany launched its fleet of U-boats.
Its submarines mostly stayed on the surface and submerged only to attack ships with torpedoes. Germany's indiscriminate submarine warfare was a primary reason the U.S. joined the war.
