This set of textbook readers was used in the schools of the United States till 1970s. It was the first reading series to enforce strict vocabulary control over selections. William S. Gray, a renowned educational psychologist and reading authority from the University of Chicago became a senior co-author with William H. Elson in creating this series. The authors have attempted to provide an interesting, purposeful, and comprehensive reading course for children. To achieve this purpose the authors have assembled materials from the worldwide field of children’s favorite readings. Thus basic reading attitudes and habits are developed through the purposeful use of interesting and significant content. Using this series of readers, the children can learn to read first, and then read to learn in their future life.