What is the title of the influential reader published in 1836 that sold more than 60 million copies?

The title of the influential reader published in 1836 that sold more than 60 million copies is the McGuffey Readers. These books were created by William Holmes McGuffey and were designed as a series of grade-level readers for children. They became widely adopted in American schools and were significant in shaping the reading curriculum of the 19th century. The McGuffey Readers included moral lessons, well-crafted stories, and a focus on phonics and comprehension, which contributed to their popularity and longevity in educational settings. Their impact reached generations of students, making them a cornerstone of American educational materials during that era.