The Office of the Messrs. Rockefeller (OMR) materials document the increasing role assumed by John D. Rockefeller, Jr. in the management of Rockefeller affairs and amply document his business and philanthropic affairs. They also chronicle the entrance of JDR Jr.'s sons, John D. 3rd, Nelson A., Laurance S., Winthrop, and David, into the world of business, philanthropy, civic leadership, and politics as they joined the office.