Along with the urbanization increase of the 1950s, the arrival of the maquiladoras in the 1960s, and NAFTA in the 1990s, came the proliferation of colonias along the US-Mexico border.
Today, the United States-Mexico border region is dotted with hundreds of rural subdivisions characterized by extreme poverty, ‘substandard’ living conditions, reflecting situations and environments that one would normally associate with developing countries. In this regard, Texas, the state that holds the majority of colonias, has over 1800 of them.
> Colonias are considered semi-rural subdivisions of substandard housing lacking basic physical infrastructure, potable water, sanitary sewage, and adequate roads.
> Colonias are unincorporated, unregulated, substandard settlements that are burdened by the lack of environmental protection
> Colonias do not have access to traditional homeownership financing methods and therefore consist of ramshackle housing units built incrementally with found material on expanses of undeveloped land
> Colonias have a predominant Latino population where 85 percent of those Latinos under the age of 18 are United States citizens.” 
Although the majority of the colonias emerged in the 1950s, with an increase of the border population responding to new employment opportunities, the boom of colonias happened in response to NAFTA and the maquila boom of the 1990s.
Facing a housing shortage a realizing many of the new border residents could not afford houses in the formal urban realms, nor had access to traditional home finance mechanisms, land developers began subdividing peri-urban areas where law enforcement was weak or nonexistent.
Foreign to this type of informal urbanization and land development, the Cranston-Gonzalez National Affordable Housing Act (NAHA) created a federal definition for colonias, listing them as an “identifiable community” in Arizona, California, New Mexico, or Texas within 150 miles of the U.S.-Mexico border, lacking decent water and sewage systems and decent housing and in existence as a colonia before 1989.
In colonias, land is sold under a contract for deed arrangement, which means that ownership remains with the seller until the total purchase price is paid. Most of these are undocumented and often including a high rate of interest. Most of the land developed for housing lacks basic the provision of basic services such as water, sewage, and electricity.
According to assessments conducted by the Texas Water Development Board (TWDB), 24 percent of households in Texas’s colonias are not connected to treated water and use untreated water for drinking and cooking. In addition, TWDB has estimated a cost of $147.9 million to provide water services to these households, $80 million to provide indoor plumbing improvements as 44% of the homes in the colonias have outhouses or cesspools and $467.3 million to provide wastewater service.
Approximately 13 percent of the border’s housing units are mobile homes, or constructions that do not meet code, yet are incremental in nature allowing families to, little by little, consolidate, grow and improve their home.
Poverty in the border region is particularly high in Texas, nearly 30 percent. Poverty is not new to the border — nearly half (47 percent) of the border counties have had poverty rates of 20 percent or higher since 1960. The vast majority of these persistent poverty counties are located in Texas.
Although the majority of residents are of Hispanic decent -about 97 percent- there is a misconception that a large percentage of the border population are not U.S. citizens. According to the 2000 Census only 12 percent of border residents are non-U.S. citizens, compared to 7 percent for the nation as a whole. This finding is supported by other research that estimates 85 percent of colonias residents are citizens of the United States.
Rather than being illegal, colonias are considered “extra-legal,” as they circumnavigate the law rather than violating it. Approaches on how to address colonias are very polar, bringing an interesting debate to light. Although there are some who clearly choose sanitary housing over the need for housing, others more partisan to a libertarian approach, acknowledge that this urban informality brings a much needed flexibility to the system, providing alternatives to those who do not have a choice….
In my opinion Colonias are a perfect example to prompt a view South.
 Taken form Wikipedia, citing :
> Larson, J. E. (2002). Informality, Illegality, and Inequality
> United States Department of Housing and Urban Development. State Community Block Grants: Colonias. Washington DC: U.S. Department of Housing and Urban Development. Retrieved March 6, 2014
> Neal, D. E., Famira, V. E., & Miller-Travis, V. (2010). Now is the Time: Environmental Injustice in the U.S. and Recommendations for Eliminating Disparities (pp. 48-81). Washington DC: Lawyers’ Committee for Civil Rights Under Law.
> Dabir, S. (2001). Hardship and hope in the border colonias. Journal Of Housing & Community Development, 58(5), 31.
 Larson, J. E. (2002). Informality, Illegality, and Inequality
 Colonia prevention: https://www.texasattorneygeneral.gov/consumer/border/colonias.shtml