*Party division totals are based on election day results.
Democrats retained control of the 64th Congress (1915–1917) with reduced margins. The U.S. declared neutrality as warring European powers ordered food and arms while a mutual blockade interfered with U.S. shipping. Congress increased military preparedness and established a U.S. Shipping Board. Domestic reforms included a ban on child labor and an eight-hour workday for railroad employees. Congress also promised eventual independence for the Philippines and granted full U.S. citizenship to Puerto Ricans.