This series consists of Ordnance survey files recording changes in local government boundaries in England, Wales and Scotland.
The first series of county files started in 1940 and continued until 1974 when local government in England, Wales and Scotland was reorganised after the Local Government Acts of 1972 and 1973. A second series of county files was started thereafter to cover the new administrative areas.
These files are arranged into two types. The first contains copies of all acts, orders or statutory instruments affecting boundaries; and a sketch diagram or extract from an administrative areas diagram showing the new and cancelled boundaries and names and titles with their grid references. Each of these files has an index at the front which includes a brief outline of changes made to boundaries. The second type of file contains correspondence with local authorities and other interested parties about proposed changes to boundaries.