Henry Pickering Walker (1911-1984) was an American historian and the author of Historical Atlas of Arizona. Walker's research concerns the importance of wagon freighting in the economic development of the American West. The time period under discussion begins in 1822 with early merchandise wagons making the trip from Franklin, MO to Santa Fe, NM. It concludes in 1880 when the railroad system reached the mining towns of Montana. Charts and graphs follow the extensive bibliography, and some show the number of wagons by year while others depict comparative prices of wool and grocery items such as coffee, bacon, sugar, and flour.
The collection includes a typescript of Walker's Ph.D. dissertation for the History Department at the University of Colorado, written in 1965.