Under the leadership of George Ellery Hale (see Mount Wilson Observatory webpage on Hale and Wikipedia on Hale ) and with funding from the Carnegie Institution of Washington, the Mt. Wilson Observatory (MWO) opened in 1904 as a solar observatory. Solar observations continue at MWO today. Additional telescopes and facilities came later including but not limited to the 60-inch telescope (1908), and the 100-inch Hooker telescope (1917).
Up until I wrote this article, when I thought about the Mt. Wilson Observatory, I have to be honest and say that I knew only about Hale and Hubble. Among Hubble’s notable discoveries were the discovery of the galaxies outside of our own galaxy and the expansion of the Universe. The Day We Found the Universe by Marcia Bartusiak has a good discussion of the construction of the Mt. Wilson Observatory and her telescopes as well as Hubble’s work and a couple of other astronomers who worked at Mt. Wilson Observatory in the early twentieth century. The MWO has a nice webpage of the history of the MWO (with links), there is also a nice timeline of the first 100 years of MWO (with links) where you may learn about some of the work that has been done at the MWO, some notable astronomers, and current uses of MWO.