Why is it significant that many jim crow laws reference gender as well as race?

It is important because the status of women at the time wasn't much better than that of African Americans.
Black people were discriminated against on the basis of their skin color; however, similarly, women were discriminated against on the basis of their gender. Just because they were women, they were considered to be 'lesser beings' that men, and thought they should be subservient to men's will. So at the same time that activists were fighting for the rights of people of color, they were also fighting for women's rights.

Adjective clauses  begin with words such as that, when, where, who, whom, whose, which, and why. an essential (or restrictive)  adjective clauseprovides information that is necessary for identifying the word it modifies. so for example*** wrong= i the man gave me direction. example right ( i the man who gave me the  direction.