This series consists of photographs of models of six inventions of Robert McCormick (1780-1846), best known as the inventor of a reaping machine. According to material in this collection, the models were made by Leander James McCormick before 1894. The series includes correspondence and other material related to Leander McCormick's donation of the original models and related materials to the University of Virginia.

The brothers William Sanderson McCormick and Cyrus Hall McCormick exchanged letters which provide valuable background on the beginnings of the McCormick reaper business and its development, as well as significant insight into the paternal family line of Robert R. McCormick.