The department is named in honor of BrigadierJuan Antonio Lavalleja, who had distinguished military and political action in the country's independence.
The department was created on June 16, 1837, with part of Cerro Largo and Maldonado departments. It was first named as Minas. In March 1888, it was asked that the Chamber of Deputies raised the settlement hierarchy of the village of Minas to be a town and to change the department's name to Lavalleja. The first was approved. From then, and until December 26, 1927, when the name was changed to Lavalleja, widespread debates about the matter were held. There was political will to designate a department under the name of the head of the Liberation Crusade, but not at the expense of Minas, even considering creating a new department named Lavalleja, being rejected afterwards.
Geography
Most of the north border of the department is formed by the Olimar Chico River and Olimar Grande River. Most of the middle and north part of the department is crossed by many streams, flowing from northwest and south directions towards the northeast of the department, all being tributaries of Río Cebollati, which flows to the northeast and discharges into Lake Merín, a natural border with Brazil. These streams, from north to south, are: Arroyo Gutiérrez, Arroyo de los Molles, Arroyo de los Chanchos, Arroyo Polanco, Arroyo Barriga Negra, Arroyo Tapes Grande, Arroyo Marmarajá and finally Arroyo Aiguá, which forms most of the east border of the department. In the south of the department, flowing from east to west is Santa Lucía River with its tributaries, Arroyo del Soldato, Arroyo Campanero Grande and Arroyo Verdún. Another stream in the south is Arroyo Solís Grande, which forms part of the natural border with Canelones Department and flows south discharging into the Río de la Plata near Gregorio Aznárez.
The south part of the Cuchilla Grande hillrange crosses the department from the south to northwest. In the south and near Minas, there are two important tourist attractions, the hills of Cerro Arequita and Cerro Verdún (which is also a pilgrimage sanctuary). A bit further to the north is the hill Cerro Espuelitas.
The railroad track Montevideo-Minas is active only for cargo trains of the Línea Minas. Another track, following the path of Route 14 through the department, is active for cargo trains from Montevideo of the Línea Río Branco, which continues into Brazil.
