Letterpress copy books for McCormick's outgoing correspondence for much of the time he controlled one of America's largest and most influential corporations. Many of these letters and telegrams are in reply to incoming letters found in McCormick Mss 1C. Each volume is preceded on the microfilm by its own index. In addition, all pages from each letter of the alphabet were filmed together on Reels 70-72 to provide a consolidated reference aid. A copy of this reel list pertaining to the letterpress books is located on Reel 70.
