The 1881 completion of the Washburn Observatory in Madison

Located at 1401 Observatory Drive on the University of Wisconsin–Madison campus, the Washburn Observatory was completed in 1881. It was named after the former Wisconsin governor, Cadwallader C. Washburn. In 1876, the Wisconsin State Legislature passed an act to provide for deficiencies in the University fund income, which included a provision for astronomy instruction and an observatory. The site, which was previously surrounded by a vineyard and orchard, was chosen to be removed from the city of Madison with the university campus acting as the divider.

Construction on the observatory began in May 1878. A contract was given to Alvan Clark to build a telescope with a diameter of 15.6 inches, which was the third largest in the United States at the time. James C. Watson was appointed the first director of the observatory. He oversaw the completion of the original building and provided funding for a students' observatory and a solar observatory. After Watson died in 1880, he was succeeded by Director Edward S. Holden from 1883 to 1886, and then by George C. Comstock from 1886 to 1922.

Following the tenure of George C. Comstock, Joel Stebbins became the Director in 1922. Under his leadership, the observatory became a focus for work on photoelectric photometry and the study of variable stars. After Stebbins retired in 1948, Albert Whitford became the director and helped persuade the faculty to fund the new Pine Bluff Observatory, which was dedicated in 1958. Today, the observatory is home to the UW-Madison College of Letters and Science Honors Program, and the telescope is still used by students and the public during viewings.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons