The United States established its first direct diplomatic relationship with Cambodia on June 29, 1950, with the appointment of Donald R. Heath as Envoy Extraordinary and Minister Plenipotentiary. Heath presented his credentials to King Sihanouk on July 11, 1950.
The US Legation opened in Phnom Penh on November 14. Operations were initially conducted from the renowned Hotel Le Royal until a Legation office and U.S. Information Service library were established in a new location.
The Legation was raised to Embassy status on June 25, 1952, at which point Heath became the first U.S. Ambassador to Cambodia.