Vassar College Observatory. Located in the town of Poughkeepsie, New York State, USA, this observatory was completed in 1865. It was the first building constructed on the Vassar College campus, and along with the Main Building is a National Historic Landmark. Vassar College was founded in 1861 as a women-only college, with the first teacher appointed being the US astronomer Maria Mitchell, the first director of the observatory. The second director was the US astronomer Mary Watson Whitney. In the 1990s, astronomical research moved to a newly built observatory. Photograph published in 1922 in the US magazine Popular Astronomy.