Leaf from Lincoln's SUM BOOK (John Hay Library)

While working on a biography of his late law partner in the late 1860s, William Henry Herndon discovered from Lincoln family members that the teenaged Abraham Lincoln had created a copybook to record his self-study in arithmetic.  This copybook, entitled the “Sum Book” by Lincoln, was found and given to Herndon, who distributed its remaining pages as public artifacts and mementos of the late President.  The sum book may once have held fifty 9” by 12” leaves that were sewn with string along one edge of the book.  Only a few of the leaves survive today, of which Brown is privileged to have the one shown here, entitled “The Single Rule of Three.”  Other leaves are held by the Library of Congress, the Abraham Lincoln Presidential Library and Museum ,  the Indiana Historical Society,  Columbia University Library, Beinecke Library at Yale, and the Chicago Historical Society.

Recently, the staff of the Abraham Lincoln Papers Project discovered that Brown’s leaf and a recently rediscovered leaf held by the University of Chicago were originally part of the same page.  Learn more here:  http://dl.lib.brown.edu/lincoln/announcements.html