Most Americans are unaware that the National Education Association (NEA) — the nation’s largest teachers’ union — enjoys a rare privilege: a federal charter granted by Congress in 1906. That puts the NEA in the same elite company as storied civic institutions like the American Red Cross, the Boy Scouts of America, and the U.S. Olympic Committee.

One of the most popular charts available today tells a story: huge increases in administrative staffing, small increases in teachers and stu