Robert Cooper Grier

Robert Cooper Grier (March 5, 1794 – September 25, 1870) was an American judge who served as an Associate Justice of the Supreme Court of the United States from 1846 to 1870.

He was a member of the Taney Court and along with Samuel Nelson, was one of two "doughfaces", or Northern Democrats, on the court that were anti-abolitionists and voted in support of slavery. He concurred with the majority in the Dred Scott v. Sandford decision that the portion of the Missouri Compromise that prohibited slavery north and west of the federal territory was unconstitutional and that Congress had no authority to regulate slavery in the territories. Grier was pressured by President-elect James Buchanan to join the Southern majority in an attempt to prevent the appearance that the decision was made along sectional lines.

Despite his pro-slavery votes, he was opposed to secession of the Confederate States of America. In 1863, Grier wrote the majority opinion in the Prize Cases, that confirmed Abraham Lincoln's presidential power to institute Union blockades of Confederate ports during the American Civil War.