Peter Miller was a merchant in Para, Brazil. The collection contains his business and personal correspondence, financial and legal papers. The bulk of the correspondence is with the Colcord family of Salem, Massachusetts, and Newmarket, New Hampshire.

Folders 1 and 2 contain business and personal correspondence written to Peter Miller. With the exception of the first three letters written (in Dutch) to Miller while he was living in Rotterdam, Netherlands (1832-1833), the bulk of the letters were written to Miller while he was an agent in Para, Brazil. Miller established a business relationship with Thomas R. Colcord of Salem, Massachusetts, circa 1838; the majority of the letters were written to Miller by Thomas R. Colcord or his children, Edward H. Colcord, Thomas A.R. Colcord and his wife Eleanor, Joseph A. Colcord, or Clara A Colcord. The letters reveal much about the life of the Colcords but little about Miller's life.

Folder 3 includes shipping and personal financial records of Peter Miller. Several accounts and invoices itemize the shoes and boots handled by Miller. The legal papers in Folder 4 include his discharge from the United States Navy (1815), a copy of his will (1838), documents from Para, Brazil (1840, 1842), and an inventory of his estate following his death in 1850.