Is this an accurate picture of the teaching of Reading in America over the years?

The one part of the picture you forgot was the influx of illiterate emigrants into this nation during this time period. Most of them didn't speak English and had to be taught the language. In an effort to teach these children, teachers became frustrated and many left the profession. Some were the best teachers but they could go to work elsewhere and not hle the problem of teaching illiterate foreigners. This left the poorer teachers, which compelled a reduction in standards. This has been the case right up to today. Private schools have not had to deal with illiteracy because they were able to pick and choose their students. Consequently, their standards did not begin to sag until government meddling forced them to teach to a test instead of teaching subjects.