The Frick family papers includes papers of socially prominent Baltimore and Washington, D.C. families, primarily from the mid-nineteenth to the early-twentieth century. The three main families are the Fricks, Poultneys, and Turnbulls, but scattered items from related Sloan, Carroll, Denison, Brown, Ramsay, and Spense families are here as well. The papers include correspondence, genealogies, accounts, land papers, diaries, travel diaries, and recipe books.

This collection contains the papers of the Gorsuch and Mitchell families of "Retreat Farm," Baltimore County, Maryland. The collection consists of estate papers, including financial, legal and land records. The collection also contains diaries, medical account books, correspondence, and documents related to enslaved individuals. Other families represented include Bowen, Stansbury, Ensor, Merryman, and Matthews.