A few years ago, Ford’s Theatre in Washington, D.C., filled the center of a spiral staircase in its lobby with a tower made of books written about Abraham Lincoln. Eight feet wide, it stood three-and-a-half stories, 7,000 volumes in all, which is easily less than half of the books written about our 16th president.

If you were an impossibly fast reader and could consume a book about Lincoln every day, it would take you more than 41 years to read them all.