Stuart A. Streichler, “Grier, Robert Cooper,” American National Biography Online, February 2000, http://www.anb.org/articles/11/11-00357.html.
Grier sat on the Supreme Court for nearly a quarter century in tumultuous years. He delivered major opinions in many areas, including bankruptcy law, commerce, patent law, and federal court procedure and jurisdiction. Several of these opinions were important in his day, but few had lasting doctrinal significance. In twentieth-century ratings of Supreme Court justices, Grier is ranked as average. His opinion in the Prize Cases, recognized by Ulysses S. Grant as a "great service" in the nation's "darkest hours," stands as his most important contribution to American constitutional law.