Since the adoption of the first charter school law in Minnesota in 1991, charter schools have received considerable attention. Three U.S. presidents, Bill Clinton, George W. Bush, and Barack Obama, have all supported charters, and the Obama administration has highlighted charter schools under its Race to the Top fund and in regulations for its School Improvement Grant program. While charter schools remain a relatively small percentage of more than 96,000 public schools in the nation, they seem to receive a disproportionate amount of attention. The number of students educated in charters, though, is significant. In total, charters serve at least 10% of students in public schools. Many operate in struggling urban school systems. In New Orleans, the District of Columbia, Detroit, and Kansas City, more than 30% of public school students attend charter schools. Operating under specific state laws, charters vary in important and substantive ways; these variations often are lost in the national debate. The article concludes that there is little to suggest at this time that charter schools are academically superior to district-run schools. When examining a particular school or context, the most important questions are about the particular school or schools in question and the particular state and authorizer context within which they operate.