The manager of the theatre had invited the President to witness a performance of a new play known as “Our American Cousin,” in which the famous actress, Laura Keane, was playing. Mr. Lincoln was particularly fond of the theatre. He loved Shakespeare’s plays above all others and never missed a chance to see the leading Shakespearean actors. As “Our American Cousin” was a new play, the President did not care particularly to see it, but as Mrs. Lincoln was anxious to go, he consented and accepted the invitation. General Grant was in Washington at the time, and as he was extremely anxious about the personal safety of the President, he reported every day regularly at the White House. Mr. Lincoln invited General Grant and his wife to accompany him and Mrs. Lincoln to the theatre on the night of the assassination, and the general accepted, but while they were talking he received a note from Mrs. Grant saying that she wished to leave Washington that evening to visit her daughter in Burlington. General Grant made his excuses to the President and left to accompany Mrs. Grant to the railway station. It afterwards became known that it was also a part of the plot to assassinate General Grant, and only Mrs. Grant’s departure from Washington that evening prevented the attempt from being made. General Grant afterwards said that as he and Mrs. Grant were riding along Pennsylvania avenue to the railway station a horseman rode rapidly by at a gallop, and, wheeling his horse, rode back, peering into their carriage as he passed. Mrs. Grant remarked to the general: “That is the very man who sat near us at luncheon to-day and tried to overhear our conversation. He was so rude, you remember, as to cause us to leave the dining-room. Here he is again, riding after us.” General Grant attributed the action of the man to idle curiosity, but learned afterward that the horseman was John Wilkes Booth. LAMON’S REMARKABLE REQUEST. Probably one reason why Mr. Lincoln did not particularly care to go to the theatre that night was a sort of half promise he had made to his friend and bodyguard, Marshal Lamon. Two days previous he had sent Lamon to Richmond on business connected with a call of a convention for reconstruction. Before leaving, Mr. Lamon saw Mr. Usher, the Secretary of the Interior, and asked him to persuade Mr. Lincoln to use more caution about his personal safety, and to go out as little as possible while Lamon was absent. Together they went to see Mr. Lincoln, and Lamon asked the President if he would make him a promise. “I think I can venture to say I will,” said Mr. Lincoln. “What is it?” “Promise me that you will not go out after night while I am gone,” said Mr. Lamon, “particularly to the theatre.”