Kropelnicki, JeffreyJohnson, GraceKne, LenLindberg, Mark2022-05-112022-05-112022-05-11https://hdl.handle.net/11299/227302Historical National Boundaries displays global national boundaries for the following dates in history: 1800, 1914, 1918, 1939, 1945, 1970, 1990, 2000. Boundary changes associated with World War I (1914 - 1918) and World War II (1939 - 1945) can be viewed by turning off all other layers and toggling between the two. Data for each layer comes from a variety of sources, including historical atlases and the Library of Congress website - https://www.loc.gov/maps/.Attribution 3.0 United Stateshttp://creativecommons.org/licenses/by/3.0/us/historic country boundariesDatasethttps://doi.org/10.13020/146x-1412