Seminal contacts (on June 17, 1908) between Tibet, in the person of H.H. the Thirteenth Dalai Lama, and the White House, in the person of U.S. Minister to China William Woodville Rockhill (1854-1914), are described in an interesting page from the Library of Congress. Worth reading. I know from experience that LOC's Tibetan holdings are superb, and did you know they have a prayer wheel?
A gift from the Nyingma Sect of Tibetan Buddhism to the people of America.