See M. E. Cosenza, ed., The Complete Journal of Townsend Harris (1930, 2d ed. 1959); C. Crow, He Opened the Door of Japan (1939).
In 1846 Harris joined the New York City Board of Education, serving as its president until 1848. He founded the Free Academy of the City of New York, which later became the City College of New York, to provide education to the city's working people. A city high school bearing Harris's name, Townsend Harris High School, soon emerged as a separate entity out of the Free Academy's secondary-level curriculum; the school survived until 1942 when Fiorello La Guardia closed it because of budget constraints. Townsend Harris High School was re-created in 1984 as a public magnet school for the humanities.
President Franklin Pierce named Harris the first Consul General to the Empire of Japan in July, 1856, where he opened the first U.S. Consulate at the Gyokusen-ji Temple in the city of Shimoda, Shizuoka Prefecture , sometime after Commodore Perry had first opened trade between the U.S. and Japan in 1853. After two years of negotiation marked by deadlock and cultural clashes, he successfully negotiated the "Treaty of Peace and Commerce," or the Harris Treaty, in 1858, securing trade between the U.S. and Japan and paving the way for greater Western influence in Japan's economy and politics. He returned to the U.S. in 1861.
Townsend Harris expressed some very positive views about Japan at the end of its period of isolation:
As reported in the New York Times, when he was interviewed in 1874 by someone recently returned from Japan, his first question was, "What do the Japanese think of me?"
Harris is buried in Green-Wood Cemetery in Brooklyn, New York.
Harris also appears as the main character of several episodes of the satirical Japanese manga-based anime, Gag Manga Biyori as a desperate man with a thick accent attempting to outshine Commodore Perry's arrival in a black-hulled ship in 1853, while making preparations for finalizing the Treaty of Peace and Commerce.