The economic downturn that started in December 2007, and which has been referred to as the Great Recession, placed significant strains on all sectors of the U.S. labor market. Perhaps the most significant indicator of those strains was the steep increase in unemployment durations. The policy response to the Great Recession was both timely and extensive; a major component was the Emergency Unemployment Compensation Act of 2008 (or EUC08), which began in June 2008 and provided additional weeks of unemployment compensation (UC) benefits to workers who had exhausted their entitlements under regular state unemployment insurance (UI) programs. Although this major program in emergency benefits was the largest in U.S. history in terms of dollars of benefits paid to claimants, its details closely resembled programs adopted in many earlier recessions. This paper places the EUC08 program (together with many of its additions and amendments) into a theoretical and historical context to highlight the similarities and differences among the various programs. We provide a conceptual background for extended benefits programs by reviewing the literature on “optimal UI,” focusing most extensively on the potential duration of benefits as a policy parameter. We also provide an overview of the major extended benefits programs that have been implemented since 1970, and we summarize the key components of EUC08 and its amendments. We also quantitatively compare these extended benefits programs by summarizing their aggregate characteristics, and we provides a summary of the empirical studies of the impacts of these programs.