L'Union was founded in the 1790s after the fusion ofBelbèze andCornaudric. After leaving Spain,Napoleon's troops, under the command of Field Marshal andMarshal of the EmpireSoult, battled there against troops under the command of theDuke of Wellington. The nameSaint-Jean-de-l'Union is still spoken of, recalling the time when the communes ofSaint-Jean et L'Union were unified.
L'Union has three nursery and primary schools (Belbèze-lès-Toulouse, Borde d'Olivier and Montizalguier), and one high school (collège Georges Chaumeton, named after the former mayor).
L'Union features anolive tree celebrating the new millennium,[4] at the Town Hall. The Grand Hall of L'Union regularly welcomes artists. Its church features architecture of the nineteenth century.
L'Union has a sport club, established in 1957, called theASUArchived 21 September 2009 at theWayback Machine, with more than 5000 members and 300 organisers, and 26 different sports such asyoga,football,handball,rugby andtennis. The main park of L'Union is Parc de Malpagat, on the D888 road.
The D888 (Route d'Albi) road runs through the town in a south-west direction towards Toulouse and north-east toAlbi, roughly 75 kilometres away. The A68 motorway (Toulouse-Albi) and thePériphérique bypass the south of L'Union, served by Junctions 1 and 14 respectively.