<P> At first, Wilson tried to maintain neutrality while fighting off the submarines by arming American merchant ships with guns powerful enough to sink German submarines on the surface (but useless when the U-boats were under water). After submarines sank seven US merchant ships, Wilson finally went to Congress calling for a declaration of war on Germany, which Congress voted on April 6, 1917 . </P> <P> As a result of the Russian February Revolution in 1917, the Tsar abdicated and was replaced by a Russian Provisional Government . This helped overcome Wilson's reluctance to having the US fight alongside a country ruled by an absolutist monarch . Pleased by the Provisional Government's pro-war stance, the US accorded the new government diplomatic recognition on March 9, 1917 . </P> <P> Although the United States declared war on Germany on April 6, 1917, it did not initially declare war on the other Central Powers, a state of affairs that Woodrow Wilson described as an "embarrassing obstacle" in his State of the Union speech . Congress declared war on the Austro - Hungarian Empire on December 7, 1917, but never made declarations of war against the other Central Powers, Bulgaria, the Ottoman Empire or the various co-belligerents allied with the Central Powers . Thus, the United States remained uninvolved in the military campaigns in central and eastern Europe, the Middle East, the Caucasus, North Africa, Sub-Saharan Africa, Asia and the Pacific . </P> <P> The home front saw a systematic mobilization of the entire population and the entire economy to produce the soldiers, food supplies, munitions, and money needed to win the war . Although the United States entered the war in 1917, there had been very little planning, or even recognition of the problems that the British and other Allies had to solve on their home fronts . As a result, the level of confusion was high in the first 12 months, then efficiency took control . </P>

What country did america fight in world war 1