The earliest concrete plan for a new world organization began under the aegis of the US State Department in 1939. The text of the "Declaration by United Nations" was drafted by President Franklin Roosevelt, British Prime Minister Winston Churchill, and Roosevelt aide Harry Hopkins, while meeting at the White House, 29 December 1941. It incorporated Soviet suggestions, but left no role for France. "Four Policemen" was coined to refer four major Allied countries, United States, United Kingdom, Soviet Union, and China, which was emerged in Declaration by United Nations. Roosevelt first coined the term United Nations to describe the Allied countries. "On New Year's Day 1942, President Roosevelt, Prime Minister Churchill, Maxim Litvinov, of the USSR, and T. V. Soong, of China, signed a short document which later came to be known as the United Nations Declaration and the next day the representatives of twenty-two other nations added their signatures." The term United Nations was first officially used when 26 governments signed this Declaration. One major change from the Atlantic Charter was the addition of a provision for religious freedom, which Stalin approved after Roosevelt insisted. By 1 March 1945, 21 additional states had signed.

Source: WIKIPEDIA