Entre Ríos (Between Rivers) is a central province of Argentina, located in the Mesopotamia region. It borders the provinces of Buenos Aires (south), Corrientes (north) and Santa Fe (west), and Uruguay in the east.
The first inhabitants of the area that is now Entre Ríos were the Charrúa and Chaná who each occupied separate parts of the region. Spaniards entered in 1520, when Rodríguez Serrano ventured up the Uruguay River searching for the Pacific Ocean.
The first permanent Spanish settlement was erected in the current La Paz Department at the end of the 16th century. As governor of Asunción first and then of Buenos Aires, Hernandarias conducted expeditions to Entre Ríos unexplored lands. Juan de Garay, after founding Santa Fe, explored this area, which he called la otra banda ("the other bank").
However, the region remained entirely indigenous and uninhabited by Europeans until a group of colonists from neighbouring Santa Fe Province settled on the Bajada del Paraná in the late seventeenth century, now the site of the provincial capital. At the same time towns appear, which we now know as Nogoyá, Victoria, Gualeguay, Gualeguaychú, Concepción del Uruguay and Concordia.
Tomás de Rocamora further explored the area in 1783 under the threat of a Portuguese invasion from Brazil, and gave official status to many of the above mentioned towns. He was also the first to refer to the region as Entre Ríos. At this stage, European settlement was minimal, though during the May Revolution, the few colonists in the cities along the Paraná shore supported Manuel Belgrano and his army on his way to Paraguay.
On September 29, 1820, the leader (caudillo) Francisco Ramírez declared the territory an autonomous entity, the Republic of Entre Ríos. This lasted until his assassination on July 10 of the next year.
In 1853, in a meeting of all the provinces except Buenos Aires, Paraná was elected as the capital of the Argentine Confederation, and the leader (caudillo) Urquiza as its first president. The provincial capital was moved to Concepción del Uruguay. Defeated, Urquiza was elected governor of the province a few years later, while Domingo Faustino Sarmiento became president, but he was assassinated before finishing his mandate.
Urquiza encouraged immigration through "colonization contracts", setting up many agricultural colonies with European (mainly Volga Germans, Russians (including Russian Jews and Poles), Italians, Swiss and French) settlers. According to data of the 1903 census, of the 425,373 inhabitants of the province, 153,067 were immigrants.