The individuals and businesses listed below have generously provided information and support.  Without them, this work would have been impossible.

Abraham Lincoln Bookshop / Daniel Weinberg – Chicago, IL
Alexander Autographs / Bill Panagopulos – Chesapeake City, MD
Antebellum Covers / Ron Meininger – Gaithersburg, MD
Badwey, Rick / Frameabilia – Alexandria, VA
Barnes, Catherine – Philadelphia, PA
Benjamin, Walter & Mary (deceased) / Walter R. Benjamin Autographs, Inc. – New York, NY
CANDLES Holocaust Museum - Terre Haute, IN
Chicago Historical Society – Chicago, IL
Combs, Gary (deceased) – New York, NY
Eugene V. Debs Foundation & Museum – Terre Haute, IN
Hayes, Jim – James Island, SC
Heritage Auctions, Inc. / Sandra Palomino – Dallas, TX
Inman-Phillips, Marcy – Quincy, IL
Kaller, Seth – White Plains, NY
Lion Heart Autographs, Inc. / David Lowenherz – New York, NY
Lissandrello, John - Eatontown, NJ
Stuart Lutz Historic Documents – South Orange, NJ
Raab Collection / Stephen R. Raab – Ardmore, PA
Reese, Michael - CA
Rendell, Kenneth W., Inc. – South Natick, MA
Rubinfine, Joseph (deceased) – Cocoa, FL
Thomas, Shawn – West Babylon, NY
Zabawa, Bob – Hilton Head, SC