This town was known as La Greda , because it is resting on the Quebrada de la Greda . Notarial records Vicu�a state that in the Quebrada de la Greda, both Indian and Spanish in the sixteenth century extracted material ( clay ) for pottery , jars-making pisco .
Had that name until 1873 , at which time, following an epidemic of smallpox and product of solidarity emerged among its inhabitants as a result of the tragedy, the neighbors agreed to designate it by the name of La Union .
On March 20 of 1873 , by decree ratified the name given to the town, to designate as La Union to one of the sub-delegations of Elqui Department
