Who argued that the equal protection clause found in the fourteenth amendment already included women citizens

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 the equality provisions contained in the Civil Rights Act of 1866, which guaranteed that all people would have rights equal to those of all citizens. As a whole, the Fourteenth Amendment marked a large shift in American constitutionalism, by applying substantially more constitutional restrictions against the states than had applied before the Civil War.

The meaning of the Equal Protection Clause has been the subject of much debate, and inspired the well-known phrase "Equal Justice Under Law". This clause was the basis for Brown v. Board of Education (1954), the Supreme Court decision that helped to dismantle racial segregation, and also the basis for many other decisions rejecting discrimination against people belonging to various groups.

While the Equal Protection Clause itself only applies to state and local governments, the Supreme Court held in Bolling v. Sharpe (1954) that the Due Process Clause of the Fifth Amendment nonetheless imposes various equal protection requirements on the federal government.