500
Ulysses S. Grant once wrote: "I had known General Lee in the old army, and had served with him in the Mexican War; but did not suppose, owing to the difference in our age and rank, that he would remember me; while I would more naturally remember him distinctly, because he was the chief of staff of General Scott in the Mexican War."
What is
U.S. Grant,
Meetings with Robert E. Lee,
9 and 10 April 1865