Junín is a city in the province of Buenos Aires, Argentina, and capital of the municipality of Junín. It has a population of 82,427 (2001 census [INDEC]) and is situated 260 km west of Buenos Aires.
Inhabited by the native Charrúa people, the site's strategic location on the Salado River made it of interest to Spanish Viceroy Juan José de Vértiz y Salcedo, who established an outpost there in the 1790s as part of a line of defense against raids by displaced natives. The location became known as El Potroso.
El Potroso was reinforced by a fort by way of an 1826 decree by President Bernardino Rivadavia, and on December 27, 1827, the citadel was established under the command of a vetrean of the Argentine War of Independence, Bernardino Escribano, as Fuerte de la Federación. The advent of Buenos Aires Province Governor Juan Manuel de Rosas led to Escribano's 1829 destitution as commander; though the intervention of an officer, Isidoro Suárez, averted a bloodbath. Suárez, a veteran of one of last battles of the War for Independence (the Battle of Junín, in Perú), inadvertently gave the failing settlement its new name by his actions: "Junín."