On February 23, Ambassador Linda Thomas-Greenfield was confirmed by the U.S. Senate to be the Representative of the United States of America to the United Nations (Record Vote Number: 61- Confirmed by the Senate by Yea-Nay Vote. 78 – 20. ) and  to be Representative of the U..S.A. to the Security Council of the United Nations (Record Vote Number: 64 –Confirmed by the Senate by Yea-Nay Vote. 78 – 21).

The Chief of Mission to USUN has the title of Representative of the U.S.A. to the United Nations, with the rank and status of Ambassador Extraordinary and Plenipotentiary, and Representative of the U.S.A. in the Security Council of the United Nations. The U.S. Mission to the United Nations was formally established with that title, by E.O. 9844 of April 28, 1947.

According to history.state.gov, the first Representative of the U.S.A. to the United Nations was Edward Reilly Stettinius Jr. who also served as 48th Secretary of State from December 1, 1944, until June 27, 1945, under Presidents Franklin Delano Roosevelt and Harry S. Truman. He oversaw the end of the Second World War in Europe and the creation of the United Nations. Previous non-career appointees to this position include Madeleine Korbel Albright (1993–1997) who went on to become the 64th Secretary of State and George Herbert Walker Bush (1971–1973) who became 41st POTUS.

The CRS says that President Eisenhower appears to have been the first President to accord Cabinet rank to his Permanent Representative, Henry Cabot Lodge Jr., in 1953. Of the 30 individuals who have served since 1946, approximately two-thirds have been accorded Cabinet rank by Presidents.

Under the Biden Administration, the USUN Ambassador has cabinet-level status giving Ambassador Thomas-Greenfield a seat on the  National Security Council. This was not the case during her most immediate predecessor. President Biden stated  that he will accord Cabinet status to Greenfield “because I want to hear her voice on all the major foreign policy discussions we have.”

The last career diplomat appointed as Chief of Mission to USUN was John Dimitri Negroponte who served from 2001–2004. Other career diplomats appointed to this position include Edward Joseph Perkins (1992–1993), Thomas Reeve Pickering (1989–1992), and Charles Woodruff Yost (1969–1971).

Ambassador Thomas-Greenfield is only the 5th career diplomat to be appointed to this position.  It looks like she is the first female Foreign Service Officer  to hold a cabinet-level position.