"When, thirty-five years ago, the Lincoln Centennial Association of Springfield, Illinois changed its character from a local organization celebrating Lincoln's birthday with an annual banquet to a research organization, the first project undertaken was an attempt to discover where Lincoln was and what he did every day of his life. In 1926 the pioneering result, a slim pamphlet, now a collector's item, Lincoln in the Year 1858, was published. Six others appeared at regular intervals (1859 and 1860 in 1927, 1854 in 1928, 1855 in 1929, 1856 and 1857 in 1930) ... The seven pamphlets, revised, were brought together in 1933 in Lincoln 1854-1861, Being the Day-by-Day Activities of Abraham Lincoln from January 1, 1854 to March 4, 1861, by Paul M. Angle, executive secretary of the Abraham Lincoln Association. The following eight years carried the chronology back to Lincoln's birth with three more volumes -- Lincoln 1847-1853 by Benjamin P. Thomas, 1936; and Lincoln 1840-1846 and Lincoln 1809-1839 by Harry E. Pratt, 1939 and 1941 -- and the series became known as one of the most useful reference works in the entire range of Lincoln scholarship. Lincoln's daily activities were chronicled by using every authentic source. In the resulting mountain of material, three sources proved most fruitful: Lincoln's writings; newspapers; and Illinois court records. The opening of the Robert Todd Lincoln Papers in July, 1947, provided much new material, and The Collected Works of Abraham Lincoln, in nine volumes, appearing in 1953, almost doubled the number of known compositions from Lincoln's pen. Revising and reprinting the chronology was a project often discussed by Abraham Lincoln Association officials, but never accomplished, as the undertaking would be large and expensive, particularly if carried through Lincoln's years as President. The Lincoln Sesquicentennial Commission, after considering other possibilities, recognized the revision and enlargement of Lincoln Day-by-Day as a research tool indispensable to future generations of students. It is singularly appropriate that an idea conceived by an organization formed to celebrate Lincoln's Centennial should be completed by an agency created by Congress to celebrate Lincoln's Sesquicentennial. The Abraham Lincoln Association generously transferred its copyright to the Commission"--Preface.