Armstrong farmed in
Connecticut near the
Housatonic River, where he learned to be a carpenter and a
stonemason. In 1945, he became a history master at
Kent School in
Kent, Connecticut, where he remained for 52 years, teaching general studies, classics, and ancient history to generations of
ninth grade students. In 1956, at the request of his school headmaster, he published his first book, a study guide called
Study Is Hard Work. Armstrong followed this title with numerous other self-help books, and in 1963 he was awarded the National School Bell Award of the National Association of School Administrators for distinguished service in the interpretation of education. In 1969, Armstrong published his masterpiece, an eight-chapter novel titled
Sounder about an African-American sharecropping family. Praised by critics,
Sounder won the John Newbery Medal and the
Lewis Carroll Shelf Award in 1970, and was adapted into a major motion picture in 1972 starring
Paul Winfield and
Cicely Tyson. Among his other novels are
The Sour Land, a sequel to
Sounder, though not labeled as such,
The Mills of God and
The MacLeod Place, the story of a multi-generational family farm displaced by the construction of the
Blue Ridge Parkway. He continued to be prolific in his writing output, mainly publishing books with historical or biblical main characters, such as
Hadassah: Esther the Orphan Queen (1972) and
The Education of Abraham Lincoln (1974). ==Death and legacy==