This subseries contains correspondence related to the administration and activities of the Saturday Club. Correspondence throughout the subseries concerns attendance at meetings, nominating new members, acceptance of membership, and election of officers.

From 1870 to 1890, Charles E. Norton, Oliver Wendell Holmes, and Richard Henry Dana, Jr. were central correspondents in their roles as club administrators. Other early correspondents include Ralph Waldo Emerson, William Dean Howells, John A. Andrew, Phillips Brooks, George F. Hoar, and Charles Francis Adams. Topics of correspondence include club issues such as ensuring attendance and discussion, as well as current events.

Edward Waldo Forbes became secretary in 1910, and was a major correspondent from that point until his resignation in 1961. Much correspondence concerns his project to collect autographs of club members who had not signed the second Saturday Club record book, as well as portraits of all club members. Other frequent topics from 1910 to 1961 include member resignations, bylaws, club meeting agendas, and luncheon arrangements. Another major topic is the club's finances, such as trusts, donations received and given, and securities. Correspondents include the Cambridge Trust Company, J.M. Forbes and Co., and members of the club's Financial Committee such as Edward W. Forbes's brother Cameron Forbes.

Correspondence related to the Saturday Club's books includes discussion of production and finances with publisher Houghton Mifflin, assignment of biographical sketches to club members by Saturday Club editors and presidents, and thank-you notes from recipients of the books. Writing The Early Years of the Saturday Club was proposed in 1906, and from 1916 to 1919 correspondence centered on its production and reception, with editor Edward Waldo Emerson a major correspondent. Planning for The Later Years of the Saturday Club then began, and correspondence focused on it from 1926 to 1928, with editor Mark Anthony DeWolfe Howe and club presidents Charles W. Eliot and Bliss Perry major correspondents. Correspondence related to preliminary preparation for The Saturday Club: A Century Completed dates from 1948 and 1950, while that related to its production dates from 1955 to 1958, primarily with editors Edward Waldo Forbes and John H. Finley, Jr.

This subseries contains Saturday Club record books, minutes and attendance records, and lists of members. The Saturday Club record books consist of two bound volumes with typescript copies. The first record book contains attendance records by meeting, notes on the adoption of club rules, and lists of people nominated and chosen for membership. The second record book includes the 1886 records of incorporation, charter, bylaws, club election reports, and summaries of meetings from 1886 to 1925. Also present are attendance cards mailed to the Union Club by members to indicate that they would be present at the next luncheon. Membership records include lists of members and material from Edward Waldo Forbes's project to collect portraits of all club members, as well as autographs of club members who had not signed the second Saturday Club record book.

This subseries consists of incorporation papers including the 1886 agreement of association and notice of first meeting, along with the 1927 publishing agreement with Houghton-Mifflin for The Later Years of the Saturday Club.

This subseries contains an account book, financial reports and statements, banking records, securities records, bills and receipts, and royalty statements. The account book was kept from 1889-1912 by Oliver Wendell Holmes and club treasurers W.W. Goodwin and Edward W. Forbes. The financial reports and statements include treasurer's annual reports and statements by W.W. Goodwin, Edward W. Forbes, and William H. Claflin. Securities records contain Edward W. Forbes' records of shares and bonds, including stock receipts and letters to stockholders. Starting in 1930, J.M. Forbes and Co. handled the club's securities, and the securities records consist only of statements from them. The securities records also include a bound volume kept by Edward W. Forbes that shows security accounting by company. Bills and receipts are for routine club activities such as lunches.

This subseries includes general notes and memos on producing Early Years of the Saturday Club, as well as drafts and research for introductory chapters, chapters on individual years in the club's history, and biographical sketches of members.

Notable biographical subjects in this subseries include Richard Henry Dana, Jr., Ralph Waldo Emerson, Oliver Wendell Holmes, Henry James, Henry Wadsworth Longfellow, Charles Francis Adams, and John Greenleaf Whittier.

This subseries consists of notes and memos from production of Later Years of the Saturday Club, and drafts and research for book chapters, including biographical sketches of club members.

Notable biographical subjects in this subseries include Charles Francis Adams, Thomas Bailey Aldrich, Richard Henry Dana, Sr., Charles W. Eliot, William Dean Howells, Henry James, Jr., William James, and Francis Cabot Lowell.

This subseries consists of notes and memos from production of The Saturday Club: A Century Completed, and drafts and research for biographical sketches of club members. Notes and memos include assignments of authors to biographical sketches, a book review of the completed book, suggested chapter mottoes, and Bliss Perry's 1942 notecards on the progress of research for the book.

Notable biographical subjects in this subseries include William C. Endicott, Edward Waldo Emerson, and Alfred North Whitehead.

This subseries contains lists of members for whom biographical sketches were to be written, Edward W. Forbes's writings on the history of the club, newspaper obituaries of Robert Frost, and biographical research materials on Edward Motley Pickman.

This subseries contains newspaper clippings on James R. Killian and biographical research and drafts on various other members.

This subseries includes notes from the publication of the club's books, lists of possible biographical sources, suggested mottoes, and research material on unidentified biographical subjects.

Member pamphlets produced for annual meetings contain lists of club officers and present members with their addresses, recent club votes, the charter and bylaws, and lists of past members with their dates of death. Sometimes the lists have been used to keep track of tasks, such as finding portraits of all members.

This subseries contains printed memoirs of club members. Some of the memoirs are also authored by club members, such as Edward Waldo Emerson and Moorfield Storey. Some were printed for private circulation, and others were published in periodicals or by historical or professional societies.

This subseries consists of book reviews of The Early Years of the Saturday Club and The Saturday Club: A Century Completed, from publications such as Harper's Monthly, The New York Times, The Boston Sunday Globe, and Newsweek. Also included is an advertising mock-up of The Later Years of the Saturday Club.

This subseries contains two printed copies of Bliss Perry's Recollections of the Saturday Club, written in 1942. Perry describes his memories of his interactions with the club and its members, atmosphere, discussions, and lunches over time.

The subseries consists of illustration mockups for The Saturday Club: A Century Completed. The illustrations contain measurements, captions, and descriptions of where they will be placed in the book.

Included are invitations; a program for Moorfield Storey's funeral service; addresses, including one by Moorfield Storey; a memoir of club member George Santayana by Joel Porte; articles, including one inscribed to Edward W. Forbes, obituaries; genealogical material; and material related to the Union Club of Boston.