Illinois

Settlement & growth (pre-1960)

Before American settlement, Illinois was home to several Native American nations, including the Illiniwek (for whom the state is named), the Miami, and later the Potawatomi, Sauk, and Fox. French explorers Jacques Marquette and Louis Jolliet arrived in 1673, establishing fur trading posts and missions at Cahokia and Kaskaskia along the Mississippi River. French control ended in 1763, and British rule was brief, as the region passed to the United States after the Revolutionary War. The 1803 Louisiana Purchase and the 1818 statehood opened Illinois to American settlers.

The first major wave of American settlers were Southerners — primarily from Kentucky, Tennessee, and Virginia — who moved into southern and central Illinois via the Ohio River. They were largely of Scots-Irish and English descent, bringing a rural, agricultural lifestyle and a pro-slavery leaning that led to the state’s “Egypt” region (named for its fertile soil) around Carbondale and Marion. By the 1830s, the Erie Canal and the National Road funneled Yankees from New England and New York into northern Illinois, founding towns like Galena and Rockford. These groups clashed politically, with the Yankee influence eventually dominating the state’s anti-slavery stance.

The 1840s through 1880s brought massive European immigration. Germans were the largest group, fleeing political unrest and seeking farmland; they settled heavily in Chicago, Belleville, and Effingham, establishing breweries, churches, and tight-knit communities. Irish immigrants, driven by the Potato Famine, arrived in the 1840s and 1850s, working on the Illinois and Michigan Canal and the railroads, concentrating in Chicago’s Bridgeport neighborhood and La Salle. Scandinavians — Swedes, Norwegians, and Danes — came in the 1850s-1890s, settling in Rockford, Moline, and Bishop Hill, drawn by farming and the emerging manufacturing sector. Poles and other Eastern Europeans arrived in large numbers between 1880 and 1920, clustering in Chicago’s “Polish Triangle” and Joliet, working in steel mills, stockyards, and factories.

The Great Migration (1910-1970) transformed Illinois’s racial makeup. Over 500,000 African Americans left the Jim Crow South for industrial jobs in Chicago, East St. Louis, and Peoria. Chicago’s Black population exploded from 44,000 in 1910 to over 800,000 by 1970, creating vibrant communities on the South and West Sides. This period also saw the rise of the city’s meatpacking, steel, and manufacturing sectors, which attracted white migrants from Appalachia and the rural Midwest. By 1960, Illinois was a manufacturing powerhouse, with a population that was 85% white, 10% Black, and less than 2% Hispanic or Asian.

Modern era (post-1965)

The 1965 Hart-Cellar Act fundamentally reshaped Illinois’s demographics by opening immigration from Asia, Latin America, and Africa. The most dramatic shift has been the growth of the Hispanic population, which rose from 3% in 1970 to 18.5% today. Mexican immigrants, drawn by agricultural work in the 1960s and 1970s, established large communities in Chicago’s Pilsen and Little Village neighborhoods, as well as in Aurora, Elgin, and Waukegan. Puerto Ricans, who are U.S. citizens, arrived in significant numbers after World War II, settling in Chicago’s Humboldt Park and Rockford. Today, Hispanics are the fastest-growing demographic group, particularly in the Chicago suburbs and downstate cities like Decatur and Champaign-Urbana.

East/Southeast Asian immigration surged after 1965, with Chinese, Filipino, and Vietnamese communities forming in Chicago’s Chinatown and the northern suburbs of Skokie, Evanston, and Naperville. Indian (subcontinent) immigration, though smaller at 2.4%, has grown rapidly since the 1990s, driven by tech and medical professionals settling in Chicago’s western suburbs like Schaumburg and Hoffman Estates, as well as near Urbana-Champaign’s university. The foreign-born share, however, remains low at 6.8% — reflecting that most growth comes from domestic migration and natural increase.

Domestic migration has been a story of loss and gain. Since the 1970s, Illinois has seen net out-migration to Sun Belt states like Texas, Florida, and Arizona, driven by deindustrialization, high taxes, and cold winters. Chicago’s population peaked in 1950 at 3.6 million and has declined to 2.7 million, while the suburbs have grown. Downstate, cities like Peoria, Rockford, and Decatur have lost population as manufacturing jobs vanished. Meanwhile, the collar counties — DuPage, Lake, and Will — have boomed, attracting both white and minority families seeking better schools and lower crime. The Black population has become more suburbanized, with significant growth in Bolingbrook and Matteson, while Chicago’s Black population has declined by over 200,000 since 2000.