Confederate Commemorative Works Inventory and Joint Resource Study Act This bill directs the Departments of the Interior, Defense, and Veterans Affairs to each conduct a full inventory of specified Confederate commemorative works, including flags and other symbols or signage, on the public lands under their jurisdiction. Using such inventories, the National Park Service shall conduct a special resource study to examine the works commemorating and interpreting the Civil War and commemorating, with respect to such war, the soldiers, people on the home front and battle lines, and related locations in the United States from 1861-1865. Among contents required to be identified by the study are historical assessments of each work, the suitability and feasibility of retaining works, identification of properties that could meet the criteria for designation as national historic sites, and an evaluation of historical research.