Сангамон өзені: тарихы, географиясы және экологиялық мәселелер

The Sangamon River is a principal tributary of the Illinois River, approximately 246 mile (396 km) long, in central Illinois in the United States. It drains a mostly rural agricultural area and runs through Decatur and Springfield. The river is associated with the early career of Abraham Lincoln and played an important role in early European settlement of Illinois, when the area around was known as the "Sangamon River Country". The section of the Sangamon River that flows through Robert Allerton Park near Monticello was named a National Natural Landmark in 1971.

The river rises from several short headstreams in southern McLean County that arise from a glacial moraine southeast of Bloomington Normal, Illinois. Part of the moraine is publicly owned as the Moraine View State Recreation Area. The river's course forms a large arc through central Illinois, first flowing east into Champaign County, Illinois, south through Mahomet, then west through Monticello and Decatur, then turning northwest to flow along the north side of Springfield. It receives Salt Creek at , approximately 25 mile (40 km) north northwest of Springfield; then the river turns west, forming the southern boundary of Mason County with Menard and Cass counties. It joins the Illinois River from the east just north of Beardstown. The Sangamon is impounded in Decatur to form Lake Decatur, constructed in 1920–1922 to provide a water supply for Decatur. This lake, formed by damming the main stem of the river, with no control over upstream land uses, has had major problems with siltation and agricultural pollution. The lake often has excessive nitrate levels from agricultural runoff. Many times the city was forced to warn people not to allow babies to consume water in Decatur because of "blue baby syndrome", Methemoglobinemia. Decatur has now installed nitrate treatment to avoid this problem. The upper Sangamon, between Mahomet and Monticello, runs along the face of a terminal moraine within the Lake Michigan Glacial Lobe, which ranges in age from 28,000 to 12,000 BP. During the glacial Woodfordian Substage (middle Wisconsin Stage), ice of the Lake Michigan Glacial Lobe advanced rapidly, leaving a terminal moraine parallel to the modern Sangamon River. In later years, he told of taking a steamship three miles (5 km) into the prairie after losing his way on the Sangamon during a flood. During his first campaign for the Illinois General Assembly in 1832, he made navigational improvements on the river a centerpiece of his platform. From 1848 to 1860, Lincoln practiced law in the Illinois Eighth Judicial Circuit, which meant he regularly crossed the river as he traveled around the circuit. The Potawatomi Trail of Death passed through here in 1838.

Despite its environmental problems, the Sangamon River is a focus of recreation for the people of Central Illinois. Key parklands along the river, moving from upstream to downstream, include Shady Rest, Robert Allerton Park, the parks bordering Lake Decatur, Rock Springs Conservation Area, Lincoln Trail Homestead State Park, Springfield's Carpenter Park and Riverside Park, the Sangamon River State Fish and Wildlife Area, Lincoln's New Salem, Saybrook, and the Sanganois State Fish and Wildlife Area. The river was mentioned in Sufjan Stevens's song "Decatur, Or, Round Of Applause For Your Stepmother!". Singer songwriter Ben Bedford references the Sangamon in several of his songs, one of which is titled after it.