Manuscript and letterpress copies of outgoing correspondence of the Mayor's Office. The letters are addressed to individuals in the city and elsewhere who were engaged in some type of business with the municipal government. Several of the volumes also include copies of the Mayor's messages to the City Council (see also the original messages arranged by councilmanic body and the copies described as Office of the Mayor, Messages to the Council). Most of the volumes are indexed, though some of the earlier editions are only partially indexed or missing one altogether. Several volumes are missing from the collection, including a number of small gaps from the Civil War and its aftermath, as well as volumes from 1913-1919.