What accounts for patterns of city adoption and abandonment of council-manager government? Despite dozens of empirical studies, we lack a systematic understanding of these forces over time because previous work has relied on cross-sectional designs or analysis of change over short periods. This article begins to fill this lacuna by constructing a historical data set spanning 75 years for the 191 largest cities with either mayor-council or council-manager governments in 1930. Event history analysis is applied to isolate adoption and abandonment trends and to provide new evidence revealing the forces that have shaped the trajectory of institutional change in U.S. cities. This analysis reveals that social context factors—in particular, economic conditions—generate both adoptions and abandonments.