These are digital boundaries for the system of Constituencies which were and are the units from which Members of Parliament are elected, and which they then represent. The system of county and borough constituencies has early origins but was not systematically mapped until the reforms introduced by the Representation of the People Act in 1832. This file represents the system as it was established following the partial review of England and Wales conducted in 1945 prior to the Boundary Commission Report of 1949. Scotland was not reviewed at this time.