David Taylor speaks about his recent book, "Working the Line," a photographic examination of the territory that is the U.S./Mexico border, organized around a series of 260 obelisks that demarcate this boundary, which were installed in the late 1880s. In the process of his work, Taylor earned remarkable access to U.S. Border Patrol facilities, agents and routine operations, giving him a unique view into overlapping issues of border security, human and drug smuggling, the continuing construction of the border fence, and its impact on the land. Ballroom Marfa was incredibly lucky to have David speak at the Marfa Dialogues conference.