An analysis of state test data by the Hechinger Report and the Courier-Journal of Louisville, Kentucky, showed that the achievement gap between white and black children in reading and math has widened since Kentucky adopted the Common Core Learning Standards in 2010.

A state that has tried and failed for decades to eradicate disparities for low-income and black students, Kentucky stepped into the national spotlight six years ago when it became the first state to adopt the new standards.

Test scores plunged when the state introduced Common Core-aligned tests in 2012, but have been edging up ever since. Yet hidden divisions that have existed for decades persist and in many cases have widened. In spring 2015, in the elementary grades, 33 percent of black students were proficient in reading, versus 58 percent of white students; in math, the breakdown was 31 percent to 52 percent, according to Kentucky Department of Education figures.