Team Nicknames History

The fields are:

Current franchise ID
Franchise ID (may the same as current one) for earlier data
League
Division (blank before divisional play)
Location name (e.g. Brooklyn, Texas)
Nickname
Alternate nicknames (blank if none for the period)
Date of the first game with this combination
Date of the last game with combination (blank if current one)
City
State

The league codes are:

NA = National Association
NL = National League
AA = American Association
AL = American League

Team Nicknames File

The Franchise Directory contains teams' annual won-lost records, standings, managers, and other data: Franchise Directory