In America’s early years, states like Ohio, Indiana, Illinois and Wisconsin were considered a part of the American frontier. But as America industrialized in the late 19th century this region became a destination for both domestic and international migrants looking for work. While many cities like Chicago, Milwaukee and Detroit became home to a multitude of ethnic communities, what united these newcomers was their commitment to finding stable, good-paying jobs.

The Great Migration

Following the abolition of slavery, former African American slaves largely moved north to cities like Chicago, Detroit and St. Louis. These people sought to escape the oppressive Jim Crow laws of the South for well-paid union jobs working in factories or stockyards. Many neighborhoods that are considered “historically” Black today were borne out of this massive migration.

The Great Migration was one of the largest and most rapid mass internal movements in history—perhaps the greatest not caused by the immediate threat of execution or starvation. In sheer numbers, it outranks the migration of any other ethnic group—Italians or Irish or Jews or Poles—to the United States. For Black people, the migration meant leaving what had always been their economic and social base in America and finding a new one. -Writer Nicholas Lemann

While Chicago’s South Side is heavily Black today, it was not always this way. Prior to the Great Migration, Chicago’s South Side was primarily made up of European immigrants. As the flow of Black domestic migrants increased in the early 20th century, tensions rose and riots broke out. The community’s existing White residents sought to block Black residents from settling in the area through direct violence, with the worst of these actions culminating in the Chicago race riot of 1919. By the end of the conflict, 23 African Americans were killed over 350 were injured and more than a thousand Black residents were forced out of their homes. Despite this hateful campaign to halt this transition, both IL-1 and IL-2 (representing parts of the South Side) are heavily Black today.

These same dynamics powered demographic shifts seen in Detroit, St. Louis and Cleveland as well. All of these cities were desperate for workers as European immigration was halted during both World Wars and African Americans moved from the South to fill that gap. As a result, today MI-13 (Detroit), MO-1 (St. Louis) and OH-11 (Cleveland) are all heavily Black congressional districts.

Hispanic Migration & The Bracero Program

While the Great Migration of African Americans from the South was the most impactful human migration in early 20th century America, the migration of Hispanics also altered the makeup of many of these congressional districts.

In 1942, the United States and Mexico began the Bracero Program: a series of laws and diplomatic agreements that eventually became the largest foreign worker program in U.S. history. These workers provided critical labor support in the agricultural and railroading industries and its participants totaled over four million when the program was axed in 1964. (While the American government no longer officially recognized the practice, the meatpacking industry informally continued the practice of importing Mexican laborers throughout the 20th century.) Due in part to these types of foreign worker programs, today IL-3 and IL-4 (once home to the largest meatpacking district in the country) are heavily Hispanic districts. In addition, Milwaukee (WI-4) and Indianapolis (IN-7) also have substantial Hispanic populations whose migration patterns were driven by labor shortages in the mid-20th century.

Teamwork Makes the Dream Work

In many of these districts, no racial group is large enough on its own to hold political power and instead residents historically relied on trade unions to organize and advocate on their behalf. Since many racial minorities were fleeing their previous homelands for the promise of good work, they identified slightly less with their ethnic backgrounds and more with their new jobs. The Union Stockyards in Chicago displayed a fantastic example of this type of coalition building. Despite the area’s racial tension in the early 1900s, a multi-ethnic working class movement eventually emerged that helped improve wages and working conditions for all workers in the city’s meatpacking industry.

The Old West Today

While all of these districts are currently represented by Democrats, many of these districts are at the forefront of the progressive movement. Two of these districts are represented my members of “The Squad”: Rep. Cori Bush (MO-1) and Rep. Rashida Tlaib (MI-12), alongside other progressive like Rep. Alexandria Ocasio Cortez. Michigan’s new 12th congressional district also stands out for holding Dearborn, MI: home to the largest Muslim population per capita in the United States. Immigration still shapes the demographics of many of these districts today as MI-12 continues to see new residents arriving from the Middle East.

Leftover Links

• Hear an eyewitness account of the Chicago Race Riots.

• Learn more about the many ethnic communities that grew around Chicago’s Union Stockyards.