400
"We, the undersigned Prisoners of War, belonging to the Army of Northern Virginia, having been this day surrendered by General Robert E. Lee, CSA, Commanding said Army, to Lieut. Genl. U. S. Grant, Commanding Armies of United States, do hereby give our solemn parole of honor that we will not hereafter serve in the armies of the Confederate States, or in any military capacity whatever, against the United States of America."
What is the letter of surrender at Appomattox Court House?