Records of Agassiz Station: correspondence and other records of Henry A. Sawyer

In 1839, the Harvard Corporation appointed William Cranch Bond, the first Astronomical Observer, to the University, thereby taking the first step in establishing the Harvard College Observatory, after which the first telescope was installed in 1847. Scholars and students had studied astronomy at Harvard since the seventeenth century, but it wasn't until a large comet sparked public interest in 1843 that donors began donating funds to build an observatory. During the tenure of the Harvard College Observatory's first three directors, William Cranch Bond (1839-1859), George Phillips Bond (1859-1865), and Joseph Winlock (1866-1875), the Observatory's research focused on lunar photography and chronometric activities. In the late nineteenth and early twentieth centuries, under the direction of Edward C. Pickering (1877-1919), research shifted from celestial mechanics and positional astronomy to astrophysics. As a result, the Observatory developed into a major research institution, focusing on photographic star surveys and spectroscopic analysis, culminating in the publication of the Henry Draper Catalogue, with spectroscopic classifications for 225,300 stars. During Pickering's tenure, many women astronomers, including Annie Jump Cannon, Henrietta Swan Leavitt, Cecilia Payne-Gaposchkin, and Williamina Fleming, performed essential research at the Observatory.

During the next several years, the Observatory became an important astronomical training and research center. Harlow Shapley, director from 1921 to 1952, inaugurated a graduate study program in astronomy. Mandating that public education be a part of the Observatory's mission, Shapley required students in the Harvard program to present lectures on astronomy to public school children. Donald H. Menzel (1952-1966) arranged a cooperative relationship with the Smithsonian Astrophysical Observatory (founded in 1890) and its relocation to Cambridge in 1955. Financial support for the Observatory expanded under Leo Goldberg (1966-1970), and in 1973 George B. Field (1972-1983) created an administrative umbrella organization, the Harvard-Smithsonian Center for Astrophysics, to coordinate the Smithsonian Astrophysical Observatory and the Harvard College Observatory's programs. Today, the Harvard-Smithsonian Center for Astrophysics continues studies in astronomy, Earth and space sciences, and science education, while the Harvard College Observatory supports Harvard's Department of Astronomy.

The Harvard College Observatory operated the Oak Ridge Observatory in Harvard, Massachusetts, which was first constructed in 1932. It featured a building and turret for a 61-inch reflector, three buildings for other telescopes, and a building with a dark room, clock room, library, storage, and quarters for observers. Using the 61-inch reflector, astronomers performed research related to detecting the motion of stars, comets, and asteroids. Radio astronomy research at Harvard began at the station in 1952 with the construction and operation of a 60-foot radio telescope funded by the National Science Foundation. The radio astronomy project was jointly managed by astronomers Bart J. Bok and Harold I. Ewen. The radio telescope allowed astronomers to study celestial objects at radio frequencies, including stars and galaxies, pulsars, and masers, and to examine the early condition of the universe.

In December 1951, the Observatory was renamed the George R. Agassiz Station in honor of zoologist and astronomer George Russell Agassiz (1862-1951). In August 1982, the Agassiz Station name was transferred to a site in Texas when the Harvard Radio Astronomy Station (established in September 1956) was officially named the George R. Agassiz Station of the Harvard College Observatory. As a result, the Observatory at Oak Ridge required updating, and its name changed again to Oak Ridge Observatory. Harvard University owned the Oak Ridge Observatory, and the Harvard Smithsonian Center for Astrophysics performed research in later years. The Oak Ridge Observatory was officially closed in August 2005.

Henry A. Sawyer (born 1892), an astrophotographer, began his career at the Harvard College Observatory in 1920, moving to Oak Ridge Station (later George R. Agassiz Station) in 1932. His chief responsibilities were observing and photographing celestial objects, including variable stars and galaxies in the Milky Way.