Polish Corridor

Creation
The corridor was used to secure  Poland's access to the Baltic Sea. This is based on U.S. President Woodrow Wilson's proposal 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. 
Disestablishment
In March 1939, Nazi German dictator Adolf Hitler said that Poland should agree to return Danzig to Germany. He also wanted them to build highways across the Polish Corridor. Poland rejected this proposal and got Anglo-French guarantees against Nazi German aggression. When Nazi Germany invaded Poland in September 1939 over this issue, Britain and France declared war on Nazi Germany and World War II began.

References

Category:1919 establishments in Europe
Category:1930s disestablishments in Europe
Category:History of Poland