Administrative borders
GeoJSON and shapefile source material is available for six reference years between 1790 and 1970.
Files
The -projected.geojson files use WGS84 coordinates. The same directories also contain source-coordinate GeoJSON. Feature counts refer to the full web-ready files and include multiple administrative levels.
| Year | Features | GeoJSON | Shapefile source |
|---|---|---|---|
| 1790 | 4,700 | Download | View folder |
| 1815 | 4,120 | Download | View folder |
| 1858 | 4,083 | Download | View folder |
| 1939 | 3,991 | Download | View folder |
| 1952 | 3,996 | Download | View folder |
| 1970 | 4,003 | Download | View folder |
Open the 1939 web map · Download overview
Fields
HdG_NAMEHistorical place or administrative-unit name.
HdG_IDENTIdentifier associated with the historical geography source.
DATEDate information carried by the source feature.
LEVEL_IDAdministrative level used to distinguish types of units.
NRSource record number.
COLORSource styling attribute retained with the feature.
Method and limitations
The collection preserves original and transformed files so that the preparation process can be inspected. Place names alone should not be used as join keys. Check the reference year, administrative level, and HdG_IDENT value before matching other records.
Differences can arise from the source edition, manual digitisation, coordinate transformation, or the treatment of administrative hierarchy. The files should not be assumed to describe directly comparable units across all six years.