The Illinois Territory was established in 1809, carved out of the larger Indiana Territory. It included parts of present-day Illinois, Wisconsin, and Missouri. The territory served as a crucial area for settlement and development in the early 19th century, attracting many pioneers and settlers seeking new opportunities. In 1818, the Illinois Territory became the state of Illinois. The capital was initially located in Kaskaskia, later moving to Vandalia and finally to Springfield. The territory played a significant role in the westward expansion of the United States, contributing to the growth of agriculture and trade in the region.