This commentary is republished from The Conversation under a Creative Commons license.?

Brown v. Board of Education, the Supreme Court decision that desegregated public schools, stands in the collective national memory as a turning point in America’s fight for racial justice. But as the U.S. observes its 70th anniversary, Brown also represents something more somber: It ultimately led to thousands of Black teachers losing their jobs.

Before Brown, Black teachers constituted 35% to 50% of the teacher workforce in segregated states. Today, Black people account for just 6.7% of America’s public K-12 teachers, even as Black children make up more than 15% of public school students.

As researchers focused on education policy, teacher diversity, critical research methods and teacher quality, we believe this is an important piece of unfinished business for a country still reckoning with systemic racism. In our view, the best way to fulfill Brown’s promise and confront the national teacher shortage is to hire more teachers of color.

How Black teachers’ ranks rose and fell

Before Brown, Black children often were excluded from public schools or forced into underfunded and unsafe schools. Rather than accept these conditions, many Black communities pooled limited resources to build private schools of their own, buy curricular materials and hire Black teachers.

Conditions were vastly unequal to those for white children at the time, but the presence of Black teachers provided Black children with deep value and care.

Prior to 1954, there were about 82,000 Black teachers in the United States. A decade later, with hundreds of segregated schools closing, more than 38,000 Black teachers had been fired by white school leaders. As the community-run schools for Black children disappeared following the end of legalized segregation, so too did the Black educators who staffed them.

Brown had mandated integration for students but said nothing of their educators.

The importance of Black teachers

In the decades since, parents, social justice advocates and researchers have documented the importance of teachers of color and pleaded for teacher workforce diversity. They argue that Black teachers support student learning and social and emotional development of children of color in ways that lead to better outcomes.

One study found the presence of Black math teachers increased the likelihood that Black students enroll in rigorous math classes. Another found that Black students taught by at least one Black teacher from kindergarten through third grade were 13% more likely to graduate from high school and 19% more likely to attend college than same-race peers who did not have a Black teacher.

Still, the teacher workforce remains stubbornly white-dominated. Why? Research shows problematic certification measures, adverse working conditions and discriminatory hiring practices contribute to keeping Black people from becoming teachers or keeping their teaching positions.

Certification exams are barriers to entry

Obtaining a professional license is a critical milestone in a teacher’s career. Yet licensure policies and exams long have kept Black teachers out, similar to race-based policies such as literacy tests that once prevented Black people from voting in the segregated South.

By several measures, standardized tests have been found to be biased against people of color. Research shows they contain culturally biased questions that privilege white test-takers.

What’s more, certification and licensing exams prevent the entry of Black people into teaching and determine which teachers are retained. As a result, from 1984 to 1989, about 21,500 Black teachers lost their jobs, according to one study of the impact of reliance on licensure exams and policies.

This gatekeeping function is especially troublesome because other studies show exam results are poor predictors of teacher effectiveness. In one study, Black teachers in North Carolina with low exam scores nonetheless had positive outcomes on Black student achievement.

Difficult work conditions lead to turnover

Black teachers have the highest rate of turnover among teachers, both white and nonwhite. When asked to reflect on their careers, longtime Black teachers say they face constant racist microaggressions from fellow teachers, non-Black parents and district personnel.

Black male teachers in particular say their expertise is overlooked and that they are forced to play disciplinarian for Black boys. Other studies show Black teachers are systematically sorted into schools with fewer resources, chronic turnover and leadership instability.

Last-in-first-out hiring policies exacerbate the issue. Layoffs of this nature disproportionately affect the students most often taught by beginning teachers and teachers of color.

All of this makes teaching a precarious profession for Black educators.

Discriminatory hiring practices

Teacher hiring practices have made this cycle, and they can break it, too.

One study found equally qualified Black teacher applicants receive fewer job offers than white candidates. When hired, Black teachers are more likely to be selected by principals of color, and they, too, are a disproportionately small percentage of school leaders.

Principals say they seek teachers who best fit their school culture. Yet research shows that definitions of “fit” rely on subjective traits and personal attributes, and often this means excluding Black teachers.

The nation faces a massive teacher shortage, but there is no shortage of potential teachers of color. Seven decades after Brown, it is a lack of willingness to hire and retain them that is missing.