The Iglesia Evangélica Congregacional Argentina (IECA) was founded in Concordia, Entre Ríos Province, in 1922 by Volga Germans of the Reformed faith who had immigrated to Argentina. They could not adjust themselves to the Lutheran Church practices in the region and asked the Congregational Churches in the United States for assistance in establishing a denomination in Argentina. They received some help from the itinerant pastor Jorge Geier. The first member of the new denomination to be ordained was Carlos Holzer. In 1940, a seminary was founded in Concordia by pastor Otto Tiede.
The headquarters of the IECA moved to Villa Ballester in suburban Buenos Aires.