Bank balances, cancelled checks, invoices, receipts, tax returns, and notes related to the Arensbergs' personal finances and expenses, such as house renovations, money lent to Marcel Duchamp and Paul Renson, and museum and club memberships. Also includes copies of the Arensbergs' wills; architectural drawings for the Arensbergs' house; memos and notes by the Arensbergs and their staff; addresses; autographs; used envelopes; biographical data on the Arensbergs; and other material primarily related to their personal matters.

Also includes administrative records documenting the Arensbergs' relationship with the Modern Institute of Art (Beverly Hills, Calif.) as founders, lenders, and board members, as well as administrative records of the Blue-Four Galka Scheyer Collection Committee, a group of three individuals, Milton Wichner, Walter Arensberg, and Ruth Maitland, later replaced by Helen Freeman Corle, authorized through the last will and testament of Galka Scheyer to determine the disposition of her art collection.