Independent Poland ceased to exist in 1795 and the various insurrections to restore the Polish state were thwarted by the Germans, Austro-Hungarians, and Russians. During the First World War, Polish statesmen called upon the thousands of Polish immigrants in the United States to join the Polish Army in France, a military force funded by the French government and organized by the Polish Falcons of America and Ignacy Paderewski, the world-famous Polish pianist. Over 20,000 men trained in Canada and fought in the final months of the war on the Western front. While in France they were placed under the command of General Jozef Haller and became known as Haller’s Army. At the conclusion of the war, the Allied leaders at the Paris Peace Conference decided to send the soldiers to Poland to fight in the Polish-Soviet War to stop the western advance of the Bolsheviks. When the war ended, the United States government, with the influence of Secretary of State Robert Lansing, funded the return of the soldiers to their homes in the United States. This dissertation focuses on questions of the relationships among foreign policy, nationalism, and immigration and investigates forced recruitment, dissatisfaction with the cause of Polish independence exacerbated by difficult wartime conditions, nationalism among immigrant groups, ethnic identity, and anti-Semitism.