His book Justice and the Poor inspired the creation of legal aid programmes throughout the United States.
Smith was admitted to the Massachusetts Bar in 1914 and became Chief Council of the Boston Legal Aid Society.
It argued that the lack of equal justice undermined the social fabric and offered an agenda for action to provide legal aid.
Smith is also credited as the inventor of the billable hour and other administrative innovations in the legal profession.
Smith was Director of the Survey of the Legal Profession and Fellow of the American Bar Foundation.