On the other side, Wilson was determined to revise the imperialist practices of earlier administrations, promising independence to the Philippines and making Puerto Ricans American citizens. But Wilson's own policies could sometimes be high-handed. His administration intervened militarily more often in Latin America than any of his predecessors. In the European war, American neutrality ended when the Germans refused to suspend submarine warfare after 120 Americans were killed aboard the British liner Lusitania and a secret German offer of a military alliance with Mexico against the United States was uncovered. In 1917, Congress voted overwhelmingly to declare war on Germany.
With the nation at war, Wilson set aside his domestic agenda to concentrate on a full-scale mobilization of the economy and industry. During the war, industrial production increased by 20 percent, daylight saving time was instituted to save fuel, the government took over the railroad system, and massive airplane and shipbuilding programs were launched. Americans began paying a new income tax and buying Liberty Bonds to pay for the war. Although most of the power the federal government acquired over the economy during the war was based on voluntary cooperation by businesses and individuals,