Teachers call books published by Heinemann their "bibles." The company's products are in schools all over the country. Some of those products are rooted in a debunked idea about how children learn to read.
But they've made the company and some of its authors millions.
The controversial educational publishing company has sold instructional materials and professional resources in almost every state, earning at least $1.6 billion over a decade.
APM Reports sent public records requests to 100 of the largest school districts in the country about their use of Heinemann materials. We asked for records detailing how much they paid the publisher and whether they had evaluated the programs they bought. Our map shows how much each district spent on Heinemann products in the past decade and what district officials told us about the materials.