From Wikipedia:On 23 December 1871 the mission sailed from Yokohama on the SS America (1869), bound for San Francisco. Arriving in San Francisco on 15 January 1872, the group travelled by train via Salt Lake City and Chicago eventually reaching Washington, D.C. on 29 February. The mission’s stay in the United States was extended with an attempt to negotiate new treaty rights, a task that necessitated two members of the party to return to japan to obtain necessary letters of representation. Members of the iwakura mission were keenly interested in observing schools and learning more about educational policy. Tours to schools, universities and industrial locations in Boston, New York and Washington, D.C. were made as a result.