Lehigh’s astronomical observatory was built in 1868 thanks to a $5,000 gift from Robert H. Sayre, an original Lehigh trustee. Sayre’s gift also allowed for the purchase of a sidereal clock, a filar micrometer and a refractor telescope.

Charles L. Doolittle, professor of mathematics and astronomy from 1875 to 1895, conducted astronomical research in the observatory that garnered international recognition for Lehigh.

In the late 1920s, a new trolley line on nearby Brodhead Avenue resulted in vibrations that made accurate observations with the telescope impossible. Afterwards, Sayre Observatory was used only for lectures, graduate student thesis research and amateur observations with the telescope. Astronomical use of the observatory concluded in the 1950s, and the equipment was removed in 1961. In 2005, the university moved the observatory approximately 300 feet to its current location next to the Alumni Memorial Building to make room for campus enhancements.