It’s fairly easy to find current country boundaries in GIS data formats for most of the world’s countries. Sites like Natural Earth provide free GIS data in shapefile format for countries at a range of scales. Finding historical GIS data is harder to find.
Listed here are available sites that offer historical country data in GIS file formats. Historical data for individual countries is listed in alphabetical order.
World Historical GIS Data: 2000 BCE to 1994 CE
While the site is now defunct, Oracles, Thinkquest.org site consolidated a series of country boundary data into shapefiles. Created as an educational site in 1996 and acquired by Oracle in 2002, the site went defunct in 2013. Thanks to the Wayback Machine, the shapefiles of country boundaries spanning between 2000 BCE and 1994 CE can still be accessed.
The data itself should be used with caution and only for small scale projects. Created by students, the archived disclaimer page explains that the data has a spatial error of roughly +/- 40 miles and the best available information, especially for the oldest years, is not the most reliable.
CShapes World Historical GIS Data: Post WWII
The dataset is described in:
Weidmann, Nils B., Doreen Kuse, and Kristian Skrede Gleditsch. 2010. The Geography of the International System: The CShapes Dataset. International Interactions 36 (1).
The Pleiades project collects historical geographical information about places most predominately for the Greek and Roman world, and is expanding into Ancient Near Eastern, Byzantine, Celtic, and Early Medieval geography.
The data is available in CSV, JSON, and KML formats.
Access: Pleiades Historical Places
Britain Historical GIS
The site A Vision of Britain through Time from the the University of Portsmouthhas made historical boundary information for counties, parishes, and constituencies for England, Wales, and Scotland available in shapefiles format.
The GIS data cover a variety of timeframes in the 1800s and 1900s. The county information is available for free but the constituencies and parishes are offered under restricted access.
Access: A Vision of Britain through Time
China Historical GIS
Last updated in December of 2016, the Harvard Yenching Institute and Fudan Center for Historical Geography offers free access to historical GIS data for China data of a database of populated places and historical administrative units for the period of Chinese history between 221 BCE and 1911 CE.
Access: China Historical GIS
Japan Historical GIS Data
Harvard also offers historical boundary data from the 1500s to 1800s for Japan.
Access: Japan Historical Data
United States Historical GIS Data
The National Historical Geographic Information System (NHGIS) provides a wide range of historical datasets covering the United States dating back to 1790.
These include: “population, housing, agricultural, and economic data, along with GIS-compatible boundary files, for geographic units in the United States from 1790 to the present.
Access: NHGIS data
The Atlas of Historical County Boundaries provides shapefiles and KMZ files which cover historical county boundaries for the entire US and by state. The data was created in 2010 by the project of the William M. Scholl Center for American History and Culture at The Newberry Library in Chicago. The Atlas is a compilation of the “creation and all subsequent changes (dated to the day) in the size, shape, and location of every county in the fifty United States and the District of Columbia.”
Access: Historical County Boundaries
Colonial Spanish America
The HGIS de las Indias site (Spanish language) features thousands of boundary files covering colonial Spanish America from 1701 – 1808.
From the site: “more than one thousand base maps are now available for the territories of smaller provinces and jurisdictions (Corregimientos, mayoralties, sub-delegations, council jurisdictions …) in three moments: 1701, 1750 and 1800.“
Access: HGIS de las Indias