We estimate a Stock/Watson index of economic activity to assess U.S. business cycle volatility since 1867. We replicate the Great Moderation of the 1980s and 1990s and find exceptionally low volatility also in the Golden Age of the 1960s. Postwar moderation relative to pre-1914 occurs under constant but not time-varying factor loadings, suggesting structural change toward more volatile sectors. For comparable series, the U.S. postwar business cycle was as volatile overall as under the Classical Gold Standard, but much less so during the Great Moderation and the Golden Age.