Henry D. Washburn, a soldier, congressman, and explorer, settled in Vermillion County circa 1850, where he taught school, practiced law, and held county office. During the Civil War, he rose to colonel of the 18th Indiana Volunteer Infantry and later brevet major general, serving with distinction at Pea Ridge and Vicksburg. During Reconstruction he served as a U.S. Representative from 1866 to 1869. After President Grant appointed him Surveyor General of Montana Territory in 1869, he led a crucial exploration of the Yellowstone wilderness in 1870 that named major features, including Old Faithful. The Washburn Expedition became the pivotal event in Yellowstone's period of definitive exploration and helped lead to its designation on March 1, 1872 as the first national park.