Robert C. Morris, "Curtis, Benjamin Robbins," American National Biography Online, February 2000, http://www.anb.org/articles/11/11-00202.html.
Curtis used English precedent, state law, and the Missouri Compromise to show that Scott's residence in Illinois and the Wisconsin Territory had made him a free man. In the process he defended the right of Congress to exclude slavery from the northern part of the Louisiana Purchase. As support for his argument he cited John Marshall concerning federal power over the territories and pointed out fourteen distinct instances of congressional legislation on slavery in the territories between 1789 and 1848. Contrary to Taney's majority opinion, he concluded, the Missouri Compromise line was constitutional and valid.