In response to widespread perceptions of problems associated with congressional earmarks, reform efforts began in late 2006 and continued through 2010. This essay summarizes those problems, explains the distribution of earmarks within Congress, and documents their rise and relative fall between 1991 and 2010 using government and public interest group databases. The author explains and critiques earmark reform policies, including congressional rules, initiatives taken by the congressional appropriations committees, and reforms pursued by the George W. Bush and Barack Obama administrations. Congressional rules and committee-initiated reforms have been most effective, resulting in significant improvements in earmark transparency and accountability. The number and dollar value of earmarks first dropped noticeably in fiscal year 2007 after an earmark moratorium, and then stabilized as reforms were implemented. It is premature to conclude that these levels will continue or that reforms will alter the policy content of earmarks or their distribution among members of Congress.