Today, AHS serves as the steward of state history, fulfilling its mission to collect, preserve, interpret, and disseminate the history of Arizona and the West.

Established by an Act of the First Territorial Legislature on November 7, 1864, the Arizona Historical Society (AHS) is Arizona’s oldest historical agency. Architects of the Territory’s code of laws realized they were making history and that it was important to preserve a record of their activities. One of their earliest actions was to create the means for documenting the past and recording contemporary events as they unfolded. This became the Arizona Historical Society, formed to collect and preserve "all facts relating to the history of this Territory."

http://www.arizonahistoricalsociety.org/museums/welcome-to-pioneer-museum-flagstaff/