Since the second half of the 20th century, the main economic activity in El Ejido has been characterized by intensive agricultural exploitation. This is primarily with the greenhouse
production of vegetables, giving the municipality the name of the “Sea of Plastic”.
The history of this population that was dedicated to agriculture is linked to the archaeological site of Ciavieja, which was listed in the General Catalog of Andalusian Historical Heritage in 2017; it records that there were numerous settlements ranging from prehistory to Roman times.
From the Neolithic and Copper Ages (with traditions of the so-called Culture of Almeria), there is evidence of the existence of a village dating from the 3rd millennium BC. Examination of the ceramic remains of the time indicates that the village thrived during that period, while its decline is recorded by the end of the Bronze Age with the culture of Argar. Likewise, the site was occupied by a Punic community in the 5th century BC, which lasted until the Roman conquest.
The Roman past of El Ejido is in the city of “Murgi”, dating between 70 and 74 AD. It was a prosperous population at both economic and social levels.
At this Roman site, remains of thermal baths, a mosaic, a possible circus, local coinage and tombs have been found.
It is estimated that the town was completely abandoned in the 4th century due to migrations that were travelling inland.
During the Middle Ages, the land was developed to support livestock activity, with the construction of numerous reservoirs that today are part of the cultural heritage of the city. The land became depopulated after the War of the Alpujarras (1568-1570) with the expulsion of the Moorish.
The Modern Age came with the expansion of cereal cultivation in the interior during the 17th and 18th centuries, while the coast continued with fishing activity, the construction of traps and obtaining salt from the salt mines, as well as the construction of a defensive system against pirates. This system was composed of the castles and towers of Balerma, Guardias Viejas, Entinas and Cerrillos.
In the mid-20th century, the city experienced an exponential development of intensive agriculture
with technological advancement of the production process, mainly with vegetables, leading to increased economic and demographic activity in the area that has lasted to the present day. In 1982, the plenary session of the Corporation approved the segregation of El Ejido from "Campo de Dalias", making it an autonomous municipality.