Anna Gillingham met Dr. Samuel Orton in 1929, the same year he had criticized the "look-say" or whole-word" method of teaching reading (popularized by the new Scott-Foresman basal readers featuring "Dick and Jane") as an "obstacle to reading progress." Orton coined the term "dyslexia" to describe reading disabilities.

In 1935, Gillingham introduced a systematic and orderly approach of categorizing and teaching a set of 70 phonograms, single letters and letter pairs representing the 44 discrete sounds (or phonemes) found in English. In the years since Dr. Orton's death in 1948, this method has become known as the Orton-Gillingham teaching method. It remains the basis of the most prevalent form of remediation and tutoring for children with dyslexia, or dyslexia-like reading disabilities.