The Polish Corridor was a strip of land that was 20 to 70 miles, or 32 to 112 kilometers, wide and that existed between 1919 and 1939 in order to give the newly recreated country of Poland access to the Baltic Sea, as U.S. President Woodrow Wilson's proposed earlier in his famous Fourteen Points speech at the start of 1918. The German-majority city of Danzig was not a part of the Polish Corridor but was instead made a free city under League of Nations rule. Weimar Germany's various governments did not accept the new German-Polish border as being permanent and hoped to change this border later on through negotiations. In March 1939, Nazi German dictator Adolf Hitler said that Poland should agree to Danzig's reunion with Germany and also to the idea of building extraterritorial highways across the Polish Corridor. Poland rejected this proposal and instead got Anglo-French guarantees against Nazi German aggression. Then, when Nazi Germany invaded Poland in September 1939 over this issue, Britain and France declared war on Nazi Germany and World War II began.