Rotary and the United Nations have a long history.  Rotary International enjoys a consultative status at the UN and acts as observer at many meetings.  
Each year the UN recognizes its history with Rotary by holding a Rotary Day at the UN, open to Rotarians from all over the world.  For more about Rotary's history with the United Nations please click here
Once you have read this history,you might want to look for more in depth information on how Rotary helped find a location for the UN in NYC.