Yes, they were effective and made their documents and the rights for the people.
The United Nations replaced the League of Nations. The League of Nations was a cross-country entity that was composed of many countries in Western Europe and also elsewhere that was supposed to regulate certain aspects of life that were important for all countries on Earth. However, it turned out there were certain key shortcoming of this union of nations, and later the United Nations were developed.
Because it made the internment of certain American citizens legitimate.