Correspondence, letterbooks, memoranda books, diaries, subject files, and other papers relating chiefly to Robert's career in the U.S. Army Corps of Engineers and as a parliamentarian. Documents his service as engineer commissioner of the District of Columbia and the publication of his Pocket Manual of Rules of Order for Deliberative Assemblies (1876) commonly known as Robert's Rules of Order. Also documents engineering projects on the Delaware River (Ky. and Tenn.) and Cumberland River (N.Y.-Del. and N.J.), and in Frontera, Mexico, Galveston, Tex., Milwaukee, Wis., and New Bedford, Mass. Includes material pertaining to Robert's involvement in the Baptist Church. Correspondents include Newton R. Collamer, Mary Innis Denton, Persifor Frazer, James Allen Hardie, Lewis M. Haupt, A.A. Humphreys, Edward Judson, George H. Mendell, Joseph Thomas Robert, Joseph Gilbert Totten, Edward T. Townsend, John M. Wilson, and S.C. Griggs & Co.