Duncan is in his grave;
After life's fitful fever he sleeps well.
Treason has done his worst, nor steel, nor poison,
Malice domestic, foreign levy, nothing,
Can touch him further.

According to author Doris Kearns Goodwin, in Team of Rivals at page 723:
Lincoln read the lines slowly, marveling "how true a description of the murderer that one was, when, the dark deed achieved, its tortured perpetrator came to envy the sleep of his victim," and when he finished, "he read over again the same scene." Lincoln's ominous selection prompted [Attorney-General] James Speed to deliver [Secretary of State William] Seward's ominous warning about the increased threat upon his life. "He stopped me at once," Speed recalled, "saying he had rather be dead than live in continued dread." Moreover he considered it essential "that people know I come among them without fear."
Early that evening, the steamer passed Mount Vernon, prompting Chambrun to say to Lincoln, "Mount Vernon and Springfield, the memories of Washington and your own, those of the revolutionary and civil wars; these are the spots and names America shall one day equally honor." The remark brought a dreamy smile to Lincoln's face. "Springfield!" he said, "How happy, four years hence, will I be to return there in peace and tranquility."
Lincoln and his party arrived back in Washington, D.C. at about 6:00 p.m. that evening. The Washington Star described the president as being "in excellent health." His first stop, upon his arrival, was to visit Secretary of State William H. Seward, who was at his home in bed, recovering from a bad carriage accident. Seward had taken a turn for the worse. A high fever had developed and his medical attendants were concerned that he might not survive the injuries. Seward's wife Frances had traveled from Auburn, New York, to find her husband in a more serious state than she had expected. Doris Kearns Goodwin writes, at pages 724-5:
When Lincoln entered the room, he walked over to the far side of the bed and sat down near the bandaged patient. "You are back from Richmond?" Seward queried in a halting, scarcely audible voice. "Yes," Lincoln replied, "and I think we are near the end, at last." To continue the conversation more intimately, Lincoln stretched out on the bed. Supporting his head with his hand, Lincoln lay side by side with Seward, as they had done at the time of their first meeting in Massachusetts many years before. When [Seward's daughter] Fanny came in to sit down, Lincoln somehow managed to unfold his long arm and bring it "around the foot of the bed, to shake hands in his cordial way." He related the details of his trip to Richmond, where he had "worked as hard" at the task of shaking seven thousand hands as he had when he sawed wood, "and seemed," Fanny thought, "much satisfied at the labor."

Finally when he saw that Seward had fallen into a much-needed sleep, Lincoln quietly got up and left the room. Drained by Seward's grievous condition, Lincoln revived when Stanton burst into the White House, bearing a telegram from General Grant: "General Lee surrendered the Army of Northern Virginia this afternoon upon terms proposed by myself." It was later said that "the President hugged him with joy" upon hearing the news, and then went immediately to tell Mary.