McCormick Observatory, on Mount Jefferson near Charlottesville, became one of America’s leading late-19th-century observatories through Leander J. McCormick’s gift of a major refracting telescope to the University of Virginia. Delayed by postwar financial setbacks and the Great Chicago Fire, the project took shape after McCormick chose the university in 1877 and was completed in 1884, with dedication in 1885. Its 66-centimeter Alvan Clark refractor was then tied for the largest in the United States, and its dome was the world’s largest. The observatory became important for work on southern stars, stellar parallax, and the Milky Way, while also maintaining a long-running weather record and later serving teaching and public outreach.