 CTA led efforts to outlaw child labor in the state and enact other protections for children (1915), and to strengthen the teacher due process law (1921).In the 1940s, the union was the only major organization in California to protest against the internment of Japanese-Americans during World War II.While the National Labor Relations Act of 1935 made collective bargaining a lawful, protected activity in the private sector, it did not include public workers or teachers.