He belonged to the <a rel="mw:WikiLink" href="https://en.wikipedia.org/Massachusetts_Historical_Society" title="Massachusetts Historical Society" id="mw8w">Massachusetts Historical Society</a>, the <a rel="mw:WikiLink" href="https://en.wikipedia.org/American_Academy_of_Arts_and_Sciences" title="American Academy of Arts and Sciences" id="mw9A">American Academy of Arts and Sciences</a>, and the <a rel="mw:WikiLink" href="https://en.wikipedia.org/American_Academy_of_Arts_and_Letters" title="American Academy of Arts and Letters" id="mw9Q">American Academy of Arts and Letters</a>. Close friends included biographer <a rel="mw:WikiLink" href="https://en.wikipedia.org/Larry_Tye" title="Larry Tye" id="mw9g">Larry Tye</a>.