It’s well known that President Lincoln had many frustrations with Gen. George McClellan. But one telegram, answering McClellan’s excuse that he didn’t pursue the Confederates after the Battle of Antietam because his horses were tired, is especially illuminating. Lincoln wrote: 

“Will you pardon me for asking what the horses of your army have done since the battle of Antietam that fatigue anything?” 

Many of Lincoln’s telegrams during the war are contained in a book, Mr. Lincoln’s T-Mails by Tom Wheeler.  Many of them can be found at the Web site for the book.

(h/t: Betsy Newmark