Amistad Academy is a bright shining star in public school reform. Founded in 1999 in a renovated warehouse in a blighted New Haven, Connecticut, neighborhood by a group of Yale law school students, the 289-student charter school has won the praise of the last two federal education secretaries. Educators throughout the country have traveled to the middle school to study its success with students who have endured the ravages of urban poverty--arguably the nation's toughest educational challenge. And Amistad's strong academic performance has led the school's founders to create a nonprofit organization called Achievement First that is attempting to build a network of 30 charter schools like Amistad in three Connecticut cities and Brooklyn, New York. Amistad and Achievement First are part of an ambitious movement in American education to educate large numbers of impoverished students to higher standards than public schools traditionally have sought for them. Over the past decade, nearly four dozen new nonprofit enterprises known as charter management organizations, or CMOs, have set to work alongside Achievement First to replicate the nation's best urban charter schools, the publicly funded but independently operated schools that emerged on the reform landscape in the early 1990s. This report traces the history of a number of leading CMOs, showing how they have grown, how they have succeeded, and where they have fallen short. It documents a host of budgetary and regulatory barriers that local, state, and national policymakers will need to address if CMOs are to fulfill the expectations that are increasingly being thrust upon them. It also suggests that achieving the core mission that unites all leading CMOs--providing a great education to the most disadvantaged students--requires extraordinary levels of organizational, financial, and human resources. This lesson has important implications not just for the charter school movement, but for public education as a whole. (Contains 2 figures and 77 endnotes.)