American schools have never been able to teach everyone how to read, write, and do arithmetic. The myth that they could has arisen because schools a hundred years ago did not have to educate the least able. When the twentieth century began, about a quarter of all adults had not reached fifth grade and half had not reached eighth grade. The relationship between school dropout and intellectual ability was not perfect, but it was strong. Today’s elementary and middle schools are dealing with 99 percent of all children in the eligible age groups. Let today’s schools not report the test results for the children that schools in 1900 did not have to teach, and NAEP scores would go through the roof.