Professor Julie Langford, Ph.D., is the scientist responsible for creating and maintaining Arcadia, a garden and arboretum that supplied oxygen to Rapture and the owner of Langford Research Laboratories. Unlike most residents of Rapture, she does not seem to be spliced or have an affliction from ADAM abuse, and seems relatively normal, despite her dangerous environment. Before her descent to the underwater city, Langford was a renowned botanist and professor at the University of California Berkeley, where she had worked since the 1920s. Her research attracted both praise for its groundbreaking findings, and controversy for her "radical theories". For a time she worked for the United States government, offering assistance with various defoliation projects during the Second World War, including use against the Japanese on Iwo Jima.

Her disappearance after leaving for Rapture did not go unnoticed on the surface. A newspaper article from January 7, 1949 commented that she was still missing by that date, despite an “intensive investigation”. Although truly loving the plants and her work on the gardens of Arcadia, she eventually was forced into making it a commodity, available only to paying visitors. Andrew Ryan decided to charge citizens not only for taking a stroll in Arcadia, but also to sell the vital oxygen created by the arboretum. She accepted such decisions, as in a later audio diary she states that she would have complained, but then remembered who signed her paychecks. (Description source: https://bioshock.fandom.com/wiki/Julie_Langford). Julie is a little greedy and a true gardener to the point where she almost cares more about her plants more than the people of Rapture. Her voice sounds older than how she actually is and Julie doesn't feel threatened, unless it ruins her experiments. (Voice reference: https://www.youtube.com/watch?v=qs7bMeQu_Kc).