The Office of Indian Affairs, now called the Bureau of Indian Affairs, was first established in 1824 as part of the War Department. In 1849 it was transferred to the Department of the Interior. The Pima Agency was established in Arizona in 1859, and throughout its history was also referred to as the Pima and Maricopa Agency; the Pima, Papago, and Maricopa Agency; and the Gila River Agency.

This collection contains letters sent by A.H. Jackson of the Office of Indian Affairs, Pima and Maricopa Agency. The letters are arranged chronologically into three bound volumes. The first contains letters sent between November 25, 1882 and July 2, 1883. The second contains letters sent between July 2, 1883 and April 14, 1884. The third contains letters sent between April 19, 1884 and April 6, 1886.