The 10,000 residents are Mennonites of German and Dutch background. The ancestors of these Mennonites had lived in West Prussia until the end of the 18th century, in the Black Sea region of the Ukraine until 1874 and in Manitoba, Canada until 1926, before settling in Paraguay. Loma Plata with a population of about 3500 is the largest town within the colony and is the administrative centre. The emigration from Canada to Paraguay was a reaction to the introduction of universal, secular compulsory education in 1917 requiring the use of the English language, which the more conservative Mennonites saw as a threat to the religious basis of their community.
A second impetus was the Canadian settlement act, which prevented the form of cooperative farming that was practised in Russia. In 1919 a delegation was sent to South America to find a new home. The Paraguayan state was interested in opening the vast undeveloped Chaco to industrious settlers and made a considerable number of concessions to the delegation. Concessions included freedom from military service, the right to run their own German language schools, a far reaching guarantee to autonomously manage their own affairs within the jurisdiction of the colony without government interference, absolute religious freedom and an open emigration policy allowing more Mennonites settlers. The Mennonites bought the necessary land at an inflated price from the Argentine firm Casado, one of the largest landholders in the Chaco. 1743 settlers came to Paraguay from Canada in 1927.
In the 1950s there was an exodus back to Canada because of unfavourable living conditions and in response to the conservatism of the colony. In the past decade, Menno has had a rapidly developing economy and good public image. Canadian Mennonites are returning and the colony is also an attraction to Paraguayans outside the Mennonite colonies.
An economic upswing in the central Chaco began in the 1980s when the agricultural co-operative, with the help of World Bank credits, invested in dairy production. Introduction of the drought- and heat-resistant Buffalo Grass from North America in 1955 created the foundation of an extensive cattle industry and the construction of the Trans-Chaco Highway to Asunción in 1965 were significant predecessors to economic growth. An important factor in the economic improvement was the reform of the school system and a general liberalisation.
ASCIM has 300 members, of which half are Mennonites and half indigenous. The governing board of the non-profit association consists of 30 indigenous and 32 non-indigenous representatives. The number of indigenous residents is now about 25,000 and growing, numbering more than the Mennonite population. Although Mennonites and indigenous people have worked closely together for a long time and some of the latter learnt to speak the Plautdietsch language of the settlers, further mixing of the two cultures has not occurred. Christian mission work among the indigenous groups often becomes a competition between the missionary effort of the Mennonites and the Paraguayan Roman Catholic missionaries.