A comparison of Chicago public school students’ standardized test scores in 2009-2014 with those of public students across the U.S. reveals two striking patterns. First, Chicago students’ scores improved dramatically more, on average, between third and eighth grade than those of the average student in the U.S. This is true for students of all racial/ethnic groups. The average Chicago student’s test scores improved by roughly 6 grade-level equivalents in the 5 years from third to eighth grade. Second, at each grade level in grades three through eight, Chicago students’ scores improved more from 2009 to 2014 than did the average scores of all students in the U.S. Test scores rose in Chicago by roughly two-thirds of a grade level from 2009 to 2014, compared to an increase of one-sixth of a grade level nationally. Again, this was equally true for black, Hispanic, and white students. These patterns do not appear to result from increasingly test-aligned instruction or from changing city demographics and enrollment patterns.