Lat/Long: 40.0000, -89.8333
Petersburg, Illinois is the county seat of Menard County. Situated on the Sangamon River, twenty miles northwest of Springfield, Petersburg originated as a 160-acre tract surveyed and platted in 1832-33. The village did not prosper, so the original proprietors sold the site to others, who recorded a new plat in February 1836. When the Illinois General Assembly established Menard County in February 1839, settlers made Petersburg the seat of government. In February 1841, the General Assembly incorporated Petersburg as a town. Abraham Lincoln and his law partners handled nearly 400 cases between 1839 and 1860 in circuit and county courts located there.
An Act to Establish the Counties of Menard, Logan, and Dane; Survey of Petersburg, Illinois; An Act to Incorporate the Town of Petersburg; The History of Menard and Mason Counties, Illinois (Chicago: O. L. Baskin, 1879), 292-93, 297-99; Webster's New Geographical Dictionary (Springfield, MA: Merriam-Webster, 1988), 947; Martha L. Benner and Cullom Davis et al., eds., The Law Practice of Abraham Lincoln: Complete Documentary Edition, 2d edition (Springfield: Illinois Historic Preservation Agency, 2009), http://www.lawpracticeofabrahamlincoln.org.