To collect social, demographic, electoral and linguistic data for each of 118 British and Irish counties in the period 1851 - 1966, in order to study national development in the UK and Ireland. Variables County. Population: growth, proportion aged 65 and over, sex ratio, density, marriage rate, per capita income, proportion in agriculture/manufacturing/middle class/civil service, proportion who were female domestics. Proportion urban, city size, index of ethnic diversity*, vote residual and income residual. Proportion voting Conservative, Labour, Liberal, Nationalist Party. Proportion Celtic speakers. Religiosity, literacy. Proportion of Church of England, non-conformists, Roman Catholics. Proportion English born, Welsh born, Scottish, Irish and French. Voting turnout, birth rate, infant mortality rate. *See Hechter (AJS 79 2 Sept 1973). Please note: this study does not include information on named individuals and would therefore not be useful for personal family history research.