History of Poland. President Wilson was one of the advocates for Polish independence after World War 1. This site has some background.
From the site:
Independence for Poland was one of the 14 points enunciated by President Woodrow Wilson during World War I. Many Polish Americans enlisted in the military services to further this aim, and the United States worked at the postwar conference to ensure its implementation.
However, the Poles were largely responsible for achieving their own independence in 1918. Authoritarian rule predominated for most of the period before World War II. On August 23, 1939, Germany and the Soviet Union signed the Ribbentrop-Molotov nonaggression pact, which secretly provided for the dismemberment of Poland into Nazi and Soviet-controlled zones. On September 1, 1939, Hitler ordered his troops into Poland. On September 17, Soviet troops invaded and then occupied eastern Poland under the terms of this agreement. After Germany invaded the Soviet Union in June 1941, Poland was completely occupied by German troops.