Gen McClellan on 'Dan,' alias 'Dan Webster,' alias 'Handsome Dan,' aka 'that devil Dan.' [Wikipedia]
The Philadelphia Times, of 10 January 1897, quoting the ASPCA journal "Our Animal Friends":
General McClellan's favorite warhorse, usually called Dan, was a dark bay, about 17 hands high, well bred, with good action and never showing sign of fatigue, no matter how long the course. He was an extremely handsome, showy animal, with more than ordinary horse sense. Dan was a very fast walker – an important requisite in a commander's charger – but a disagreeable accomplishment so far as his staff were concerned, as their horses in general were kept on a slow trot.
After the war Dan became the family horse at general McClellan's country house in Orange [NJ], and seemed to be proud of his position, performing his duties well and easily. On one occasion, when driven to a neighboring estate by two ladies of the general's family, and left untied, as usual, at the door, Dan came to the conclusion that they had remained long enough for an afternoon call, so, declining to waste any more time there, he trotted back to his stable, carefully turning out to pass carriages and other vehicles met on the way home. Dan died and was buried in Orange.
The general said of him: "Dan was on of those horses that could trot all day long at a very rapid gait, which kept all other horses at a gallop. He earned from the aids the title of 'that devil Dan' – a name that he justified on many a long and desperate ride before I gave up the command of the Army of the Potomac. Dan was the best horse I ever had. He was never ill for an hour, never fatigued, never disturbed under fire. The dear old fellow survived the war for many years, dying at a ripe old ate in 1870. No matter how long we might be parted – once for nearly four years – he always recognized me the moment we met again and in his own way showed his pleasure at seeing me. Even on the day of his death, which was a painless one, he still attempted to rise and greet me, but, unable to do so, he would lean his head against me and lick my hand. No soldier ever had a more faithful horse than I had in Daniel Webster-- Our Animal Friends"