The name is made of the water and the plants that stand around it: the rio, the canal that divided this territory from that of Carpi, and the saliceto, the marsh willows that grow here. It is flat land, furrowed by a dense network of drainage and irrigation canals. The territory appears as early as 772 in a document of the Lombard king Desiderius; then it belonged to the marquis Boniface, father of Matilde di Canossa, who passed it to the Church, and from the twelve hundreds to the Da Correggio, who kept the mint of their principality here, at villa Caprì. It followed the fortunes of Correggio, and in 1635 the principality went to the Este. Rio, until then, was a villa of the comune of Correggio and nothing more: it was a government decree of the fourth of December 1859, effective from the first of January of the year after, that made it a comune of its own. In 1864 it added Saliceto to its name, so as not to be confused with the other Rios of Italy.
The men who obtained that autonomy are known by name: the first mayor Luigi Nicolini, the prior don Giovanni Battista Branchetti, the lawyer Luigi Carbonieri and the landowners Brunetti, Santachiara, Terrachini, Galantini and Bernini. And the village did something few do: it put their faces on its own town hall. Pier Giacinto Terrachini modelled them in terracotta, and the eight medallions are still there, along the trabeation of the pediment of the building inaugurated in 1889. The rest of that same façade is the chronicle of the century that came after: above the main door the plaque of the eighty men of Rio who fell in the First World War; in the lunettes at the base of the colonnade the monument of the Liberation, unveiled on the twenty-fifth of April 1975, thirty years afterwards, for the seven annihilated in the camps and the twenty-one who fell fighting, with an oath cut into the stone: that the monster should not come back. In those same years, between the end of the eighteen hundreds and the beginning of the nineteen hundreds, some of the first cooperatives were founded here — the workers' mutual aid society, the wine one, the carters' one and one for the betterment of those who worked the land. The Liberty-style elementary schools of that period were demolished in 1926, and in their place went up a building that was the child of the architecture of its time.