© Economic History Society 2018 This article uses the declarations of householders in the Cadaster of Ensenada (1750–5) to calculate labour participation rates for women and men from 22 localities in inland Spain. The article establishes the actual levels of women's market activity, which are much higher than commonly assumed. This unique source also makes it possible to analyse the region's occupational structure. Due to the labour-intensive character of manufacturing work, the abundant supply of cheap labour, the diffusion of cottage industries, and the demand for commodities from internal and colonial markets, a large portion of the region's population worked in manufactures in the eighteenth century. This finding challenges standard interpretations of the Spanish economy at this time as mostly agricultural, which rely on sources that exclude women workers. Most workers in the manufacturing sector were women, and their market activity was concentrated in textile manufacturing. Once women are included in the analyses, the industrial share of employment follows a U-shaped trajectory from the eighteenth century to the twentieth century. The article concludes that the standard interpretation of structural change, based solely on empirical evidence for male workers, gives a misleading picture of when, where, why, and how structural change occurred.