MANILA — The U.S. has been recruiting foreign labor for decades — farmers, meat-packers, home healthcare workers, cooks. But now the country needs teachers, and it needs them badly.

The same conditions that have led thousands of U.S. educators to strike and protest — like stagnant wages, underfunded schools, and overcrowded classrooms — have also contributed to a long list of vacancies in virtually every state.

The Department of Education's database suggests there are 46 states with vacancies (47 if you include the District of Columbia). And each of them has sizable needs that span several disciplines. Some states need teachers in all grades for almost all subjects.

So public schools have been getting creative.

Over the past decade, school districts around the U.S. have quietly begun using the J-1 visa program, which was originally created as a means of temporary cultural exchange, to fill persistent teacher vacancies. And no country has stepped up quite like the Philippines. In 2009, there were only a handful of public schools with Filipino teachers on J-1 visas, according to data from the U.S. Department of State. Today, there are more than 500, spanning at least 19 states throughout the country.