After work with the pen concerning the great battles in the Wilderness, Carleton's great question was how to get his letters to Boston. The first bundle was carried by Mr. Wing, of the New York _Tribune_, the second by Mr. Coffin's nephew, Edmund Carleton. The nearest point occupied by the Union army, which had communication with the North by either boat, mail or telegraph, was Fredericksburg, more than forty miles to the eastward. To reach this place one must ride through a region liable at any moment to be crossed by regular Confederate cavalry, Mosby's troops, or rebel partisans. There were here and there outposts of the Union cavalry, but the danger, to a small armed party, and much more to a single civilian rider, was very great. Nevertheless, young Carleton was given his uncle's letters, with the injunction to ride his horse so as not to kill it before reaching Fredericksburg. "The horse's life is of no importance, compared with the relief of our friends' anxiety; and, if necessary to secure your purpose of prompt delivery, let the horse die, but preserve its life if you can." To make success as near to certainty as possible, young Carleton took counsel with the oldest and wisest cavalrymen. He then concluded to take the advice of one, who told him to give his horse a pint of corn for breakfast and allow the animal plenty of time to eat and chew the fodder well. Then, during the day, let the beast have all the water he wanted, but no food till he reached his destination. Fortunately, his horse, being "lean," was the one foreordained in the proverb for the "long race." The young messenger lay down at night with his despatches within his bosom, his saddle under his head, and his horse near him. The bridle was fastened around his person, and all his property so secured that the only thing that could be stolen from him without his being awakened was his hat and haversack,--though this last was under his saddle-pillow. Nothing else was loose.