Grier's performance in the Legal Tender Cases brought the situation to the crisis point. The Kentucky case Hepburn v. Griswold, 8 Wall. 603 ( 1870), came before the Court in late 1867. But a decision was not handed down until two years later, and announced in February, 1870. The Justices, then eight in number, had voted on the case in December, 1869. Grier's mind was wandering. In conference, at first he voted in favor of the Act and a four-four tie resulted. But on the very next case he made a ruling on legal tender in conflict with the vote he had just made in the Hepburn case. When his colleagues told him of this he changed his vote. Thus the final vote was five to three against the validity of the greenbacks. Grier felt that the Legal Tender Act had not been intended to apply to previous contracts, and the case might be disposed of without holding the act unconstitutional. But Chief Justice Chase, and the other majority Justices, held it clearly did cover prior contracts, and Grier reluctantly went along with them.
Resignation was clearly in order. Grier's disability had already become the subject for commentary on the floor of Congress during debate on a judiciary bill. A reference was made to "one of the most eminent members ... [of the Court] who is not able today to reach the bench without being borne to it by the hands of others." Judicial pensions had been liberalized as well. All Grier's colleagues, led by Field, urged that he step down. He agreed to do so in December, 1869, the resignation to take effect the following February. He died six months later in Philadelphia, which had been his home since his appointment to the Court.
Grier was a large man, over six feet, with a ruddy complexion and jovial countenance which hid what could be at times an explosive temper. He was not a man of "exquisite refinement," as might be said by a nineteenth century biographer of his subject, but Edward Bates' negative appraisal is not borne out by other observers: "Mr. Justice Grier is a natural-born vulgarian, and, by long habit, coarse and harsh." If one may discount his final four or five years on the Bench, Grier may be rated among that large and amorphous middling group of judicial craftsmen who neither lead nor are completely dominated by others. Before the Civil War, Grier was one of the props of the Taney Court, with its due regard for the rights of the states. In the Prize Cases he demonstrated the depth of his commitment to the preservation of the Union.
No biography or scholarly article has yet been written of Justice Grier. Material for this essay was drawn from the following two sources: David Paul Brown , The Forum; or Forty Years Full Practice at the Philadelphia Bar ( Philadelphia, 1856), and Francis R. Jones, "Robert Cooper Grier," 16 Green Bag 221 ( 1904).