The number of teachers who walked out of classrooms and onto picket lines to demand higher pay, smaller class sizes and increased funding for K-12 students was unprecedented, according to education historians.

The movements in places like Arizona, Kentucky, Oklahoma and West Virginia galvanized educators around the country, prompting thousands of them to run for office in the 2018 midterm election.

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But as 2019 approaches, teachers are setting up to ring in the new year by continuing to wrestle with the same old issues.

Already some 31,000 educators in Los Angeles, the second-biggest school district in the country, are planning to walk out on Jan. 10 after the Los Angeles Unified District and the United Teachers Los Angeles failed to reach an agreement over issues including pay, class size, testing and charter schools.