This machine-readable version of John Williams' <i>Digest of Welsh Historical Statistics</i> is the result of a collaboration between the Statistical Directorate of the National Assembly for Wales, the History Data Service and the Centre for Data Digitisation and Analysis at Queen's University Belfast. John Williams' <i>Digest of Welsh Historical Statistics</i> is intended to provide a service for those working on the history of modern Wales. It arises from a belief that the quantitative element is a necessary and important part of the historical record; from an awareness that it was an aspect that was particularly inaccessible for scholars of Welsh history; and from a conviction that some encouragement in the use of quantitative material was necessary. It is modelled on the two volumes dedicated to British historical statistics: Mitchell, B.R. and Deane, P. (1962) <i>Abstract of British historical statistics</i> and Mitchell, B.R. and Jones, H.G. (1971) <i>Second abstract of British historical statistics</i>. Canals. Mileage and costs at opening, South Wales and North Wales, 1700-1945 Canals. Iron carried on the Monmouthshire, 1820-1840, and Glamorganshire, 1817-1840, canals Railways. Mileage, traffic and capital, 1848-1938 Roads. Mileage, 1860-1974 Road vehicles. Licences current, by type, 1926-1974 Ports. Total tonnage of coasting vessels belonging to main ports, 1709-1751 Ports. Foreign trade, value of imports and exports, main ports, 1857-1972; shipping registered at main ports, 1814, 1815, 1829 Ports. Cargo traffic through main ports, 1911-1974 Ports. Cargo traffic, by type of cargo, main ports, 1922-1974 Ports. Shipping movements: Cardiff, arrivals and departures, 1841-1886; main ports, arrivals 1911-1938, arrivals and departures, foreign and coastal, 1946-1971 Civil aviation. Movement, by type, passengers and freight carried, Welsh air ports, 1938-1974 Communication. Number of letters and parcels posted, 1938-1975; number of broadcast receiving licences in force, 195 4-1975 Please note: this study does not include information on named individuals and would therefore not be useful for personal family history research.