"The United States has had relations with Oman from the early days since American independence. The U.S. merchant ship Ramber made a port visit to Muscat in September 1790. The United States signed a Treaty of Amity and Commerce with Oman in 1833, one of the first of its kind with an Arab state. This treaty was replaced by the Treaty of Amity, Economic Relations, and Consular Rights signed at Salalah on December 20, 1958. Oman sent an official envoy to the United States in 1840. A U.S. consulate was maintained in Muscat during 1880-1915, a U.S. embassy was opened in 1972, and the first resident U.S. Ambassador arrived in July 1974. Oman opened its embassy in Washington in 1973. Sultan Qaboos was accorded formal state visits in 1974, by President Gerald Ford, and in 1983, by President Ronald Reagan. President Bill Clinton visited Oman in March 2000. Career diplomat Marc Sievers has been Ambassador to Oman since late 2015."
CRS Report for Congress, RS21534