On April 21, 1865, The New York Times published a letter given to them by John Wilkes Booth's brother-in-law, John S. Clarke.

(Musical break.) MR. WATTENBERG: Hello, I’m Ben Wattenberg. In his new and best-selling book, April 1865, author Jay Winik argues that the most critical month in American history was April 1865.

General Lee and 21 confederate generals on horseback ... signed at Appomattox Court House on April 9, 1865: We, the undersigned Prisoners of War, belonging to the Army of Northern Virginia ...