The passage of the Public Employment Relations Act (PERA) in 1947 permitted government employees, including government school teachers, to organize for the first time into unions and engage in collective bargaining. Prior to PERA's passage, it was illegal for government entities to recognize or bargain with a public-sector union.19

The modern era of aggressive teacher unionization, however, did not begin until 1965, when the Michigan Legislature amended PERA with Public Act (PA) 379.20 PA 379 eliminated the penalties levied against public employees who illegally went on strike. Prior to the passage of PA 379, striking government employees were deemed to have terminated their employment. Though these new amendments to PERA did not legalize strikes by government employees, they substantially weakened the ability of public employers to withstand the pressure from union-initiated work stoppages.21 By 1967, 36 school districts did not open school on time due to striking teachers.22 PA 379 granted school employee labor unions extensive power over schools and students.

Prior to the 1960s, the MEA and its national affiliate, the National Education Association, were broad-based professional associations of educators that included teachers, administrators, professors of education, and virtually anyone else with a professional interest in education. Over the past several decades, however, these professional organizations have transformed themselves into labor unions for various classifications of school personnel, including non-teachers. Their primary focus on professional development shifted to issues related to school employee compensation and terms and conditions of employment—a natural development for any labor union. This fact is also demonstrated by the MFT's affiliation with the AFL-CIO, an industrial labor union for truck drivers, postal workers, plumbers, and others.

From 1963 to 1993, school employee labor union membership more than tripled from 963,720 to over 3,100,000.23 This dramatic increase in unionized public school employees coincided with the passage of state laws giving school employee labor unions the power to demand recognition as exclusive bargaining agents for all teachers in newly formed bargaining units.