This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book reviews the bases through which the state exercises at its discretion considerable control over workers’ organizations. It analyzes strike activity in Brazil as it increased in frequency and intensity from 1945 to 1963 while undergoing fundamental changes in composition. The book examines the geographical distribution of strikes and changes in the occupational composition of strikers over the 1945–1980 period. It also analyzes economic and political factors as determinants of strikes for the period 1945–1980. The book examines the decade of the 1980s when the patterns of strike activity reflected a period of political transition from military to civilian rule under conditions of chronic economic instability. It looks at the Brazilian case in the light of three important approaches to strike analysis: the economic perspective, the industrial relations model, and the political organizational approach.