The Mill Avenue historic district reveals stories of the economic and social development of Tempe, including its formation around Hayden's Ferry. The commercial district connects us to the shifting terrains of agriculture, commercial development, and tourism that characterize the broader history of the Salt River Valley. The rapid growth of the region led to multiple periods of revising the landscape and re-imagining its future, as well as efforts to preserve the architectural heritage of Tempe and the valley.

Taking a closer look at Tempe’s downtown streetscape reveals much of this history: Tempe Butte carries the legacy of Hohokam civilization; the San Pablo Barrio shows the aspirations of early Hispanic settlers; the bridges and flour mill reveal Charles Hayden’s vision for an agricultural settlement that would be built in the churches, banks, warehouses, and businesses that popped up along Mill Avenue. Other structures, such as the Tempe Hardware Building and the Casa Loma Building tell us about the efforts to preserve the historic streetscape of Tempe in the face of the urban redevelopment that swept the region in the 1970s. Ultimately, Mill Avenue provides a window into how Tempe has evolved, and also it reveals how tensions between preservation and development shaped post-war American cities more broadly.