Court justice, provided geographic and political balance. Finally, Lincoln's Treasury Secretary, Salmon P. Chase, became Chief Justice. Lincoln believed Chase was an able jurist, would support Reconstruction legislation, and that his appointment united the Republican Party. Foreign policy Lincoln named his main political rival William H. Seward as Secretary of State, and left most diplomatic issues in his portfolio. However Lincoln did select some of the top diplomats as part of his patronage policy. He also closely watched the handling of the Trent Affair in late 1861 to make sure there was no escalation into a war with Britain. Seward's main role was to keep Britain and France from supporting the Confederacy. He was successful after indicating to London and Paris that Washington would declare war on them if they supported Richmond. Assassination John Wilkes Booth was a well-known actor and a Confederate spy from Maryland; though he never joined the Confederate army, he had contacts with the Confederate secret service. After attending an April 11, 1865 speech in which Lincoln promoted voting rights for blacks, Booth hatched a plot to assassinate the President. When Booth learned of the Lincolns' intent to attend a play with General Grant, he planned to assassinate Lincoln and Grant at Ford's Theatre. Lincoln and his wife attended the play Our American Cousin on the evening of April 14, just five days after the Union victory at the Battle of Appomattox Courthouse. At the last minute, Grant decided to go to New Jersey to visit his children instead of attending the play. On April 14, 1865, hours before he was assassinated, Lincoln signed legislation establishing the United States Secret Service, and, at 10:15 in the evening, Booth entered the back of Lincoln's theater box, crept up from behind, and fired at the back of Lincoln's head, mortally wounding him. Lincoln's guest, Major Henry Rathbone, momentarily grappled with Booth, but Booth stabbed him and escaped. After being attended by Doctor Charles Leale and two other doctors, Lincoln was taken across the street to Petersen House. After remaining in a coma for eight hours, Lincoln died at 7:22 in the morning on April 15. Stanton saluted and said, "Now he belongs to the ages." Lincoln's body was placed in a flag-wrapped coffin, which was loaded into a hearse and escorted to the White House by Union soldiers. President Johnson was sworn in later that same day. Two