Just as students returned to school from their winter vacations, teachers in Los Angeles were ready to leave. Working in the second largest school district in the U.S., they were prepared to go on strike after failed negotiations in their quest for smaller class sizes, higher pay and increased funding for school counselors and nurses.
The Los Angeles dispute can be seen as a sign that the issues behind last year’s wave of walkouts—education cuts and low teacher pay, among them—aren’t resolved. But the story of teacher strikes in the U.S. goes back much further than that. Some historians have seen recent events as a resurgence of teacher activism that has roots in the 1960s and ’70s.
In the first half of the 20th century, the American Federation of Teachers and the National Education Association maintained no-strike policies. But as teachers faced the perpetual problems of difficult working conditions and lack of support for public education—and as conditions improved for other unionized professions—many chapters ignored that practice. Teacher strikes started to occur with greater frequency. More than 50 such strikes took place from 1946 to 1949, up from only a dozen in the first half of that decade, according to the Encyclopedia of U.S. Labor and Working-Class History.
Teacher strikes picked up during the next 30 years, even in the face of state laws that outlawed them. There were more than 1,000 such strikes involving more than 823,000 teachers from July 1960 to June 1974, according to the same encyclopedia. By the late 1970s, 72% of public-school teachers were covered by collective-bargaining agreements, and union membership soared.
Jon Shelton, an associate professor at the University of Wisconsin—Green Bay and author of Teacher Strike! Public Education and the Making of a New American Political Order, says several forces contributed to a spate of teacher strikes through the 1970s, including the fight for collective-bargaining rights, conflicts over inequality in segregated schools, and political and economic pressures that simultaneously forced districts to cut costs and unions to fight for increased wages.
“In some cases, you had teacher strikes that lasted two and three months because the conflicts between the school districts and the teacher unions there were so pronounced,” Shelton says.
In 1973, there were simultaneous teacher strikes in Chicago, St. Louis and Philadelphia—the last of which lasted nearly two months. In 1981, teachers in Ravenna, Ohio, concluded a five-month strike. In 1987, a teacher strike in the small town of Homer, Ill., came to a bitter end after eight months. To this day, it appears to hold the record for the longest teacher strike in U.S. history. But more than 30 years later, similar issues in Los Angeles reflect an unfinished battle over the rights and role of teachers.
This appears in the January 21, 2019 issue of TIME.