Polygon shapefile of El Salvador’s departments representing census data for 1971, 1983, and 1992: 1.) Total population by department in 1971 data was derived from John Paxton, ed., The Statesman's Year-Book: Statistical and Historical Annual of the States of the World for the year 1981-1982 (London: Macmillan Press, 1981), 430; 2.) Registered displaced population by department and municipality in 1983 was derived from John Mullaney, “Aiding the Desplazados of El Salvador: The Complexity of Humanitarian Assistance” report (Washington, D.C.: U.S. Committee for Refugees, Fall 1984), Table 1 “Overview of the Displaced Population (Registered) by Department as of October 31, 1983”. Table 1 contained the following elements: Department name, Total number of municipalities, Number of municipalities with displaced population, Total displaced population, and Proportion of national total of displaced persons. According to Mullaney, sources for Table 1 were the National Commission for the Assistance to Displaced People (CONADES), Office for Social Promotion, and Department of Investigations and Statistics. This publication is in Box 206, Folder 1 of the Julian Samora Collection at the Benson Latin American Collection; 3.) Total population by department in 1992 data was derived from “El Salvador”, 09-27-1992, https://www.citypopulation.de/en/elsalvador/cities. The census data presented in the site was derived from the Dirección General de Estadística y Censos.