United Nations (Earth-2915)

The United Nations (UN) is an international Earth-based organization, and the predecessor of the UNSC and the Unified Earth Government. By the 26th century, the UN has been absorbed into a branch of the UEG and has become a largely vestigial entity, acting as a local administrative body among the national governments of Earth.

Inception
The idea of a United Nations system of global governance began in 1920 after the end of World War I. The brainchild of American President Woodrow Wilson, the purpose of the League of Nations was to spark economic development and to keep the peace after the destruction of the war. However, this organization would soon collapse without the support of the United States Congress and growing tensions caused by the Great Depression of the early 1930s. Its ultimate downfall came with World War II which the League was completely unable to prevent. The concept, however, had not been discredited. In 1941, US President Franklin D. Roosevelt named the Allies the "United Nations" with the name being kept after the Second World War's end as a peacekeeping organization comprised of the members of the military alliance. This was a significant time in human history as it sparked growing tensions between the two superpowers of the time, the United States of America and the Union of Soviet Socialist Republics which would lead to the space race and the development of many advanced technologies as part of a technological arms race. Had humanity not endured the Cold War, it is likely that humanity would have been even less prepared for the interstellar age and the inevitable wars that would follow.

The UN began as an international organization that described itself as a "global association of governments facilitating co-operation in international law, international security, economic development, and social equity." It was founded officially on June 26, 1945 after the end of the Second World War at the signing of the United Nations Charter by 51 countries, replacing the previous "League of Nations."

UN government
By the time humanity began colonizing the other planets of the Sol System in the late 21st century, the nations of Earth were not yet united under a single government, though the United Nations held considerable power over humanity. In order to tackle the social, economic and technological challenges that accompanied space colonization, the UN created the Unified Earth Government in 2075. Then a transnational assembly of brilliant minds and political figures, the UEG initially lacked actual power over Earth's nations.

Source

 * https://www.halopedia.org/United_Nations.