High Quality Content by WIKIPEDIA articles! Thomas R. Cornelius (November 16, 1827 – June 24, 1899) was a prominent American politician and soldier in the early history of Oregon. A native of Missouri, he moved to the Oregon Country with his family as a young man where he fought in the Cayuse War and Yakima Indian War against the Native Americans. He settled in Washington County near what later became Cornelius, named in his honor.