Before he was elected Senator (but never served), John Curtiss Underwood was appointed judge of the U.S. District Court of Virginia. In 1866, he presided over the grand jury that indicted Confederate President Jefferson Davis for treason, and he later denied bail to Davis because he was in military custody. In 1865, he was elected to the Senate by the Virginia Legislature but could not serve because the state had not yet been readmitted to the Union.