“Old Main” was the first building erected at Gustavus Adolphus College in Saint Peter, Minnesota, when its cornerstone was laid on August 12, 1875. Contracted to O. N. Ostrom and constructed from Kasota limestone, the total cost of the building was estimated at $25,000. Old Main was completed in 1876 and dedicated on October 31 of that year. Originally referred to as the “School Building,” as more buildings were erected, it became known as the “Main Building” and by 1905, it became commonly referred to as "Old Main." (wikipedia.org)