With fears of Indian attacks abated, Illinois began to rapidly expand after the War of 1812. The war kept the population around 12,000 in 1814, but by 1820 the state population increased about 450 percent, reaching 55,211. Veterans of the war in Illinois from other states returned with their families.¹ As Reynolds, himself a veteran, wrote, “The soldiers from the adjacent States, as well as those from Illinois itself, saw the country and never rested in peace until they located themselves and families in it.”² The federal government encouraged War of 1812 veterans to settle in Illinois, gifting 160 acres to settlers in western Illinois between the Illinois and Missouri Rivers, north of the American Bottom.³

Perhaps the most critical encouragement of Illinois settlement was the opening of public land sales in 1814. The first land office opened in Kaskaskia in 1804 but spent a decade sorting out disputed French land claims. Shawneetown opened the second land office in 1812. The third land office opened in 1816 in a new community in the Goshen settlement, Edwardsville, itself not officially incorporated until 1818. Before the public land sale, most settlers either owned French land claims or squatted, hoping their improvements would grand them eventual ownership. In numerous cases land offices approved squatters’ claims.⁴ With the public sale, prospective land owners could purchase as few as 80 acres for $2 an acre from the federal government. To ensure orderly and undisputed sales, surveyors were required to delineate boundaries. Under the northwest ordinance, the whole of the Northwest Territory was subdivided into ordered, square township and ranges.⁵

The prospect of cheap land and the possibility of independence were attractive to many hoping for a fresh start after the war. The war’s end also brought economic hardship throughout the nation, drawing many to a territory nearing statehood. This was particularly true for poor southerners during the rise of The Cotton Kingdom. Yeoman farmers could not compete with wealthy plantation owners, and many moved to free states and territories. Though Illinois had slavery in the early nineteenth century, unlike the antebellum south it was not endemic to the economy. Among those fleeing slavery was poor Kentucky farmer Thomas Lincoln who left with his family for Indiana and later to Illinois. These settlers’ opposition to slavery contributed to the peculiar institution’s death in Illinois.⁶

Most of the people of 1820 Illinois had a southern background, having settled the southern portion of the state. Though the population was concentrated in the American Bottom, other settlements were scattered throughout the Mississippi and Ohio Rivers, and settlements were rapidly expanding inward and northward. Steamboats started coming up and down the Mississippi and Ohio Rivers, bringing not only more settlers, but trade goods and economic ties to the east.

All of this expansion led to calls for statehood, especially after Indiana became a state in 1816. However, the Northwest Ordinance required a population of 60,000, about twice what Illinois had. Congressional representative Nathanial Pope convinced Congress to lower the requirement to 40,000 as it had for Ohio. Most importantly, Pope arranged to have Illinois authorities do the official population count in 1818. To their chagrin, Illinois did not have 40,000 people in 1818, a more accurate estimate would be about 36,000. As a result, census counters creatively stretched their numbers using a variety of strategies – such as counting travelers as residents, deliberately overestimating the population of distant communities, and patriotic Illinoisans volunteering to be counted twice. This resulted in a count of 40,258, good enough for statehood.

Yet the population likely exceeded 40,000 the next year, reaching 55,211 in the 1820 federal census.⁷ The population continued to skyrocket through the 1820s and early 1830s thanks to both high birthrates and migrations to Illinois. The state census of 1825 showed 72,866 people,⁸ the 1830 federal census 157,445,⁹ and the 1835 state census 269,974.¹⁰ The rise in population came with increasing commercialization of the Illinois economy, as more and more steamboats shipped surplus crops and livestock throughout the country and brought eastern manufactured products to Illinois. The industrial revolution that began in England reached the St. Louis region upon the arrival of the first steamboat in 1817. 23 steamboats served the Mississippi in 1818, 89 in 1822, and 198 in 1831. Though road transportation was still expensive and unreliable in comparison, it too improved in the 1820s.¹¹ Illinois even began to have railroads by the late 1830s.¹²

The most dramatic shift though was the rise of Chicago in the north. Illinois was not even meant to have access to Lake Michigan under the Northwest Ordinance: the northern border was drawn from the lake’s southern tip. Pope however lobbied upon statehood to have the northern border extended far enough north for Illinois to build a canal from the Illinois River to Lake Michigan. With the Erie Canal completed in 1825 that connected New York City to the Great Lakes, this canal would further connect eastern ports with the Mississippi River. Chicago was located at the center of this trading network and further cemented ties between St. Louis and the growing industry of the north.¹³ Construction began on the Illinois & Michigan Canal in 1836 and finished in 1848.¹⁴ With the rise of Chicago as one of the nation’s most massive metropolises, largely settled by Yankees and immigrants, southern influence on the state diminished.

The final bout of Indian violence in Illinois occurred in 1832, when a band of Sauks, Fox, and Kickapoos led by the Sauk leader Black Hawk crossed into Illinois from Iowa. Their intentions were likely peaceful, having suffered the previous winter from dwindling food supplies. Black Hawk and his followers hoped to farm corn in northern Illinois. They were not met peacefully. An armed militia went north to force them back to Iowa, including both William B. Whiteside and a young Abraham Lincoln. The future president did not see the resulting bloodshed. Some Indians not part of Black Hawk’s band took advantage of the fighting and attacked white civilians. After Anglo-Americans crushed any remaining Indian resistance, lingering Indians in northern Illinois ceded their last territory in Illinois. The final removal of Native Americans from Illinois in the 1830s was so sweeping, that today Illinois has no Indian reservations.¹⁵

All of these changes brought about the end of the frontier in Illinois.Though still largely rural with many areas still to be settled, by the 1830s Illinois had lost many of its frontier characteristics. With them went the lush vegetation and wildlife the first settlers saw in the 1780s.