America sided with the French and British because of the actions of the German government. One of the things that the Germans did was allowing the sinking of the merchant ships by their fleet of submarines (U-boats). Secondly, the Germans offered Mexico incentives to join their cause. President Wilson declared war but also told Germany to settle their differences in a civilized and diplomatic manner. America has a long history with the French and British because many of them can count their history back through the roots of their ancestor’s. So this is why America sided with the French and British in World War I. However, the most important reason America sided with the French and British was due to the fact of the money that was coming from France and England.