Alfred Abraham Knopf Sr. was an American publisher of the 20th century, and co-founder of Alfred A. Knopf, Inc. His contemporaries included the likes of Bennett Cerf and Donald Klopfer, and Frank Nelson Doubleday, J. Henry Harper and Henry Holt. Knopf paid special attention to the quality of printing, binding, and design in his books, and earned a reputation as a purist in both content and presentation.