Includes personal and professional correspondence, subject files, memos to staff members, invitations to Cullen and the Newberry and speeches by Cullen.

Correspondence series is organized by organization or person. Correspondence sent by administrative personnel is filed under the main point of contact's name (ie: correspondence with Mayor Richard Daley's staff about the Mayor would be under Daley, Honorable Mayor Richard). Correspondence where Cullen was cc'd (ie: where he is neither the to nor from correspondent) is filed under the name of the person who cc'd Cullen. Consequently, correspondence by trustees to their contacts is filed by trustee name.

Correspondence from law firms regarding estate planning is filed under the name of the estate (ie: "Kispert, Robert" instead of "Northern Trust").

Subject files include department files, projects, and organizations where Cullen served in some capacity (ie: Heartland Society, Modern Poetry Society).