In 1920, the League of Nations had 48 members and it 1929, it had 54.

The boxes in light blue represent the main Structure of the League of Nations. The darker blue are those that non-members can use. 

The setting up of the League of Nations was written into the Treaty of Versailles as well as other small treaties. 

Its work began in January 1920 when the Treaty of Versailles came into effect. The headquarters were chosen to be in Geneva, Switzerland, for its long tradition of neutrality. 

The League's power was severely limited by the lack of America's powerful presence. The strong isolationist views of Americans at the time prevented Wilson's dreams from becoming reality.

The League had no army of its own but had planned that countries would help it in case military action was needed. Hopefully, but unrealistically, warring countries would cede to the pressure of world public opinion, and, in extreme cases, to trade sanctions.