CTA was formed in May 1863. Earlier that year the state's fourth Superintendent of Public Instruction, John Swett, had issued a call for a "teachers' institute" in San Francisco. Once assembled, the group, numbering about 100, created the California Educational Society. In 1875, the name was changed to State Teachers' Association.
For almost five decades, several regional groups, including the Southern California Teachers Association, worked cooperatively with, but independently of, CTA. CTA filed for incorporation in 1907, and the regional groups were consolidated in 1910. A statewide governance structure was created; but the four regional entities, now called "sections," elected their own executive secretaries and staffs. Two more sections were added in 1918 and 1921. In 1971, the sections were phased out and CTA became a thoroughly integrated organization, with one governance structure and one staff.