Union de Santa Fe

The club was established by a group of fourteen former members of Santa Fe Foot-ball Club, on April 13, 1907 after a meeting held in the Baragiola family on Catamarca street. Guillermo Drenner was appointed as president of the institution. Initially the club was named "Club United" after a proposal from founding member Cayetano Bossi, who alleged that the club should represent the friendship ties of the founders. The name changed to "Unión Foot-Ball Club" in 1907, remaining until 1918 when it was translated to "Club Atlético Unión" in Spanish language.

The first shirt worn was white with black collar. In 1907 a meeting was held with the purpose of choosing the club colors. Some of the models proposed were a red, white and black striped, while other members proposed a white and red striped shirt (inspired on legendary Alumni Athletic Club uniform), which finally won after being voted by the majority.

The first match played by the team was vs a San Carlos Centro on 15 May 1907, won by Unión 4–1. Unión was also a founding member (along with Argentine, Central Santa Fe, Brown, Red Star, Sarmiento, San Justo Football Club y Estudiantes de Comercio) the "Liga Regional Santafesina", where the team won the title four consecutive times. In 1910 the club moved their field to a land on Boulevard Pellegrini and San Jerónimo. In 1911 Unión requested affiliation to "Liga Rosarina de Football" which would allow them to play with stronger teams and more competitive tournaments so teams of Liga Rosarina participated in national cups with teams from Buenos Aires. The LRF accepted the request in 1912, and Unión debuted there vs. Argentino (3–3 tie). The first win in Liga Rosarina was vs Aprendices Rosarinos with the following line-up: José Luis Peíteado; Saúl Galetti, Domingo Pallavidini; José Ayala, Alfredo González, Domingo Gómez; Gregorio Aguirre, Arturo Pérez, Manuel Montenegro, Elías Pieretti, Domiciano Roa.

On 26 November 1966, Unión was promoted to the Primera División for the first time, after defeating Talleres (RE) 3–0 and winning the 1966 Segunda División title.

Unión's supporters are called "unionistas", "tatengues", while the squad is usually nicknamed "El Tate". The colours of the club consist of red and white vertical stripes.

Managed by Juan Carlos Lorenzo in 1975, Unión made a great campaign in the 1975 championship with a group of notable players such as goalkeeper Hugo Gatti, midfielders Victorio Cocco and Rubén Suñé and forwards Ernesto Mastrángelo and Leopoldo Luque among others.

In 1979 Unión played the final matches of the Nacional championship, but lost at the hands of River Plate, because the goal scored by River in the first match (with a final score of 1–1) ended up in an average over Union according to the away goals rule applied to that tournament.

Amongst the most famous footballers who played for Unión are Leopoldo Luque, World Cup winner with Argentina in 1978, and Nery Pumpido, the goalkeeper of the national team that won the World Cup in Mexico 1986.