Johnson was admitted to the bar in 1815 and began practicing law in Upper Marlboro, Maryland. Two years later, he moved to Baltimore, Maryland, and continued the practice of law. He was a Whig in politics, and in 1821 he was elected to the Maryland State Senate. In cooperation with the Maryland law clerk of the Court of Appeals, he compiled a report of cases decided in that court titled I-7 Harris and Johnson Reports, 1800-27. He was elected to the United States Senate in 1845 where he supported the Mexican War but opposed the annexation of Mexican territory because he felt it would revive the controversial conflict regarding slavery extension. In 1849, he resigned his senate seat to become attorney general under President Zachary Taylor, serving in that capacity until Taylor’s death. In 1854, Johnson and lawyer Thaddeus Stevens obtained for Cyrus McCormick a decision upholding the validity of his reaper patent (Seymour vs. McCormick). Two years later, he appeared in court with the same parties this time opposed by Edwin M. Stanton. Johnson represented the defense in the famous case of Dred Scott v. Sanford. Johnson joined the Democratic Party, and was a southern sympathizer who attended the Washington Peace Conference. However, he opposed secession and regarded it as a treasonous act. Johnson became a U.S. Senator in 1861 and was reelected in 1862, but he did not take his seat until 1863 because President Abraham Lincoln sent him to New Orleans to investigate complaints made by the foreign consul against General Benjamin Butler. Johnson supported George B. McClellan for president in 1864 in opposition to Lincoln’s interference with border state elections and Lincoln’s issuing of the Emancipation Proclamation. However, Johnson voted for both the Thirteenth and Fourteenth Amendments, and served on the Joint Congressional Committee and the Committee of Fifteen on Reconstruction. Johnson opposed the impeachment of Andrew Johnson. In 1868, he was appointed minister to Great Britain, and the following year, he returned to the United States to continue the private practice of law until his death.
Mary Wilhelmine Williams, "Johnson, Reverdy," Dictionary of American Biography (New York: Charles Scribner’s Sons, 1964),
5:2:112-14; Bernard C. Steiner, Life of Reverdy Johnson (Baltimore: The Norman, Remington, 1914). Illustration courtesy of the Abraham Lincoln Presidential Library, Springfield, IL.