Antonia Maury was the niece of Henry Draper, and after recommendation from Mrs. Draper, was hired as a computer. She was a graduate from Vassar College, and was tasked with reclassifying some of the stars after the publication of the Henry Draper Catalog. Maury decided to go further and improved and redesigned the system of classification, but had other obligations and left the observatory in 1892 then again in 1894. Her work was finished with the help of Pickering and the computing staff and was published in 1897. She returned again in 1908 as an associate researcher.