In 1868, what was the most important reason to include the equal protection clause in the Fourteenth Amendment?

The Equal Protection Clause is part of the Fourteenth Amendment to the United States Constitution. The clause, which took effect in 1868, provides that no state shall deny to any person within its jurisdiction "the equal protection of the laws". A primary motivation for this clause was to validate and perpetuate the equality provisions contained in the Civil Rights Act of 1866, which guaranteed that all people would have rights equal to those of white citizens. As a whole, the Fourteenth Amendment marked a large shift in American constitutionalism, by applying substantially more constitutional restrictions.