^Waterman L. Ormsby, edited by Lyle H. Wright and Josephine M. Bynum, "The Butterfield Overland Mail", The Huntington Library, San Marino, California, 1991.
^Goddard Bailey, Special Agent to Hon. A.V. Brown. P.M., Washington, D.C., The Senate of the United States, Second Session, Thirty-Fifth Congress, 1858–'59, Postmaster General, Appendix, "Great Overland Mail", Washington, D. C., October 18, 1858.https://babel.hathitrust.org/cgi/pt?id=uc1.c109481050;view=1up;seq=745
^Aaron V. Brown, Report of the Postmaster General, Senate, 35th Congress, 2d Session, Ex. Doc. No. 48, Contract with J. Butterfield and Co. p. 1.
^Isaiah Churchill Woods, Report to Hon. A.V. Brown, "Postmaster General on the Opening and Present Condition of the Overland Mail Route Between San Antonio, Texas, and San Diego, California", by J.[I] C. Wood [Woods] Superintendent, Washington City, D.C., March 1858. Note: This 43-page report to the Postmaster General also contains references from Woods' day book.https://babel.hathitrust.org/cgi/pt?id=miun.aft3376.0001.001;view=1up;seq=1