Letterpress copybooks concerning affairs in Missouri and Kansas, and the operation and properties of the Leavenworth, Lawrence & Galveston Railroad of which Walker was president at the time. Many letters are addressed to J. F. Joy, Octave Chanute and to officials of the Missouri, Kansas and Texas Railroad, the Kansas Pacific line, and the Kansas City Stockyards. Volume 4 also includes a few items comprising legal opinions and some incoming correspondence.