At which city was the United Nations Organization (UNO) formally founded in 1945 through the signing of its Charter?

Introduction / Context:
The United Nations Organization (UNO) is the most important international body for maintaining international peace, security and cooperation. Questions about when and where it was founded are very common in world history and world organisations sections of competitive exams. Knowing the founding city helps place the birth of the modern multilateral system in its proper historical context at the end of the Second World War.

Given Data / Assumptions:

• The question asks for the city where the United Nations was founded.
• Options given are San Francisco, London, Paris and Moscow.
• The founding moment is the signing of the UN Charter in 1945, not later meetings.

Concept / Approach:
The key concept is that the United Nations was created after World War II to replace the League of Nations. Delegates from many countries met at a special conference to draft and sign the UN Charter. This conference, officially called the United Nations Conference on International Organization, was held in San Francisco in the United States. The Charter was signed there on 26 June 1945, and the UN formally came into existence on 24 October 1945 when the Charter came into force.

Step-by-Step Solution:
Step 1: Recall that the UN is a post Second World War organization set up in 1945. Step 2: Remember the name of the founding conference: United Nations Conference on International Organization. Step 3: Link this conference with its host city, San Francisco, on the west coast of the United States. Step 4: Compare with the options: London and Paris were important Allied capitals, and Moscow was a key capital of another Allied power, but none of these cities actually hosted the Charter signing conference. Step 5: Conclude that San Francisco is the correct city where the UN Charter was signed and where the UN was founded.

Verification / Alternative check:
To verify, you can recall that New York is the permanent headquarters of the UN, but it is not the founding city. Many history books and UN documents clearly mention that the Charter was signed in San Francisco in June 1945. The day the Charter came into force, 24 October, is celebrated as United Nations Day worldwide, further linking this period and the city with the birth of the organisation.

Why Other Options Are Wrong:
London: London hosted many important wartime meetings and is the capital of the United Kingdom, but it did not host the UN founding conference.
Paris: Paris is another major diplomatic centre, and the earlier League of Nations was strongly associated with Europe, but the UN Charter was not signed there.
Moscow: Moscow was a key Allied capital and participated in planning for a post-war organisation, yet the formal founding of the UN took place in San Francisco, not in Moscow.

Common Pitfalls:
Students sometimes confuse the location of the founding conference with the permanent headquarters in New York. Another confusion arises because many historic peace conferences were held in European capitals like Paris, leading some candidates to guess Paris automatically. To avoid this, it is useful to memorise the simple pairing: founding in San Francisco, headquarters in New York.

Final Answer:
The United Nations Organization (UNO) was founded through the signing of its Charter in San Francisco in 1945.