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Mathematical Treasure: Abraham Lincoln's Cipher Book (ca. 1825)

Frank J. Swetz (The Pennsylvania State University)

Abraham Lincoln (1809-1865), the 16th president of the United States of America, came from a rural background. It was long believed that he was self-educated and received little formal schooling; however, some emerging documents point to the fact that, indeed, Lincoln did have a formal education. Pages of a cipher book belonging to Abraham Lincoln have been discovered in various library collections, including Columbia University, Harvard University, and the Lilly Library of Indiana University. Here are two pages of this book concerning the computation of simple interest.

It is thought that the book can be dated to 1825 when Lincoln was 16 years old. The book was given by Lincoln’s stepmother to his former law partner, William Herndon, who, when Lincoln became well known, distributed them as presents to various friends.

These images are presented through the courtesy of the Lilly Library, Indiana University, Bloomington, Indiana.


Index to Mathematical Treasures


Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Abraham Lincoln's Cipher Book (ca. 1825)," Convergence (August 2019)