Papers relating to Thayer's student and teaching career at Harvard Law School, work as a practicing attorney, and involvement in professional affairs. Includes notes, financial records (1884-1891), and examination questions from his student days at Harvard College and Harvard Law School, and studies for the Massachusetts Bar Association and Carnegie Foundation on the quality and content of bar examinations and methods of teaching in American law schools.

Primarily letters from British author Leonard Merrick to American lawyer and Harvard Law School dean, Ezra Ripley Thayer. Also includes other papers concerning Merrick and Thayer.