The quality of education in the United States has been heavily criticized in part because of U.S. students’ performance on international tests, such as the Program for International Student Assessment (PISA) and the Trends in International Mathematics and Science Study (TIMSS). Although simple country averages may support such criticisms, there are many problems in comparing test scores of students in the U.S. as a whole with students in countries with very different social and educational environments. Not least of these problems is that students in the United States do not attend school in a “U.S. educational system,” but rather in at least 51 different systems, many of which have experienced very significant progress over time. The most relevant lessons for improving U.S. education may therefore be found in our successful states, rather than in other countries.