Charles M. Mackubin and Erastus Smith Edgerton formed a partnership in the fall of 1853 and opened their banking business on June 1, 1854 under the name of Mackubin & Edgerton. Their office was located at the Winslow House at Seven Corners in Saint Paul. Cashier of this bank was Fred H. Donahower, who later was cashier for many years at the First National Bank of Saint Peter. In 1856-57, Mackubin & Edgerton erected a building at the corner of West Third and Franklin Streets, a portion of which they occupied with their bank, moving in on July 4, 1857.
Mackubin left the partnership in 1858. Edgerton continued business at this office until January 1865, when he organized the Second National Bank of Saint Paul. Mackubin & Edgerton was one of several private banks in 1857-58 that endorsed notes of defunct banks to remedy the lack of currency in circulation. In issuing the notes, they neatly placed their red “M. & E.” stamp near the serial number and wrote their endorsement on the back.