We provide 16 purchasing-power-parity-adjusted estimates of U.K. and U.S. income per capita and output per worker between 1872 and 1990 based on new estimates of their price levels. Our income benchmarks depart from current estimates in four crucial respects. The United States, not the United Kingdom, led in income per capita in the 1870s. The United Kingdom kept pace with the United States through the late Victorian era. Most of the United Kingdom's relative decline occurred between 1905 and 1950. Finally, the post-1950 performance of the U.K. economy was stronger than is now estimated.We thank Michael Edelstein for getting us interested in the topic. We are also indebted to two referees for comments on the first draft. Susan Carter, Greg Clark, C. Knick Harley, Alan Heston, Peter Lindert, Robert Lipsey, Luis Locay, Bryan Roberts, Christina Romer, Richard Sylla, Jeffrey Williamson, and the participants in a seminar at the University of California, Riverside gave helpful suggestions. Finally we are especially grateful to Deirdre McCloskey for advice at an early stage.