1912年日米友好記念に東京市長尾崎行雄が桜3,000本を送ったのが始まりだ、と書かれております。
The National Cherry Blossom Festival(R) is an annual commemoration of the gift
in 1912 of 3,000 cherry trees by Mayor Yukio Ozaki of Tokyo to Washington as a
memorial of national friendship between the United States and Japan and a
celebration of the continued close relationship between the people of the two
countries.