James H. McMillen (1823-1913) was an Oregon pioneer of 1845, volunteer in the Cayuse Indian war, and resident of Washington County, Oregon. Collection consists of McMillen's manuscript reminiscences, 1910-1911, in the form of a letter to George Himes, regarding his journey to Oregon in 1845; his acquaintance with John McLoughlin and Peter Skene Ogden; and his recollections of the Whitman killings, Cayuse Indian War, and early Portland, Oregon.

Ink portraits of famous Oregon pioneers, including George Abernathy, Jonathan Bourne, Robert Gray, Joseph Lane, John McLoughlin, Joe Meek, Peter Skene Ogden, Oswald West, John Whiteaker, Narcissa Whitman, W. S. U'Ren and Jason Lee, and Oregon pioneer archetypes, such as a trapper and farmer.