New estimates of nominal earnings and the cost of living are presented and used to make a fresh assessment of changes in the real earnings of male and female manual workers in Britain from 1770 to 1870. Workers' average real earnings are then adjusted for factors such as unemployment, the number of their dependants, and the costs of urbanization. The main finding is that the standard of living of the average working-class family improved by less than 15 percent between the 1780s and 1850s. This long plateau is shown to be consistent with other economic, political, and demographic indicators.