By this time, Mr. Coffin was himself nearly exhausted, having been worn down by constant service, day and night, in one of the most exhausting campaigns on record. Knowing that both armies would have to throw up entrenchments and recuperate, he came home, according to custom, to rest and freshen for renewed exertion. Leaving immediately after the battle of Cold Harbor, that is, on June 7th, he was back again in Washington on June 22d, and in Petersburg, June 26th. The lines of offence and defence were now twenty miles long, and the great battle of Petersburg, which was to last many months, the war of shovel and spade, had begun. Mr. Coffin remained with the army, often riding to City Point and along the whole front of the Union lines, reading the news of the sinking of the _Alabama_ by the _Kearsarge_, and the call of the President for a half million of men, seeing many of the minor contests, the picket firing, the artillery duels, and learning of the splendid valor of the black troops. He came to Washington and Baltimore, when the news of Early's raid up the Shenandoah Valley was magnified into an invasion of Maryland by General Lee, with sixty thousand men behind them. Carleton, however, was not one to catch the disease of fear through infectious excitement. Finding Grant, the commander-in-chief of all the armies in the field walking alone, quietly and unostentatiously, with his thumbs in the armholes of his vest, and smoking a cigar, neither excited nor disturbed, Carleton felt sure that the raid had been anticipated and was well provided for. Both then, as well as on July 18th, when he had to argue with friends who wore metaphorically blue glasses, he wrote cheerfully and convincingly of his calm, deliberate judgment, that the prospects of crushing the rebellion were never so bright as at that moment. He concluded his letter thus, "Give Grant the troops he needs now, and this gigantic struggle will speedily come to an end."