Federation is a department of the northeast of the province of Entre Ríos in the Argentine Republic. Take the name of its head, the city of Federation. It is the seventh smallest in the province with an area of 3760 km² and the fifth most populated, with 68 736 inhabitants according to the 2010 census. It is bordered on the west by the Feliciano and Federal departments, on the north by the province of Corrientes, on the south by the department Concordia and to the east with the Oriental Republic of Uruguay.
According to the methodology used by INDEC for the 2010 census, the Federation department comprised 11 locations: Chajarí, Colonia Alemana, Colonia La Argentina, San Ramón, Colonia Peña, Federation, Los Conquistadores, San Jaime de la Frontera, San Pedro or Colonia Freitas, Santa Ana, Villa del Rosario, Colonia Santa María was considered a locality in the 2001 census, but it lost that category for 2010. Colonia Alemana, Colonia Peña, and Colonia La Argentina, were not considered places in the 1991 census., while San Ramón was not in 1991 or in 2001.