Hainesville is a village in Avon Township, Lake County, Illinois, United States. Per the 2020 census, the population was 3,546. Hainesville has the distinction of being the oldest incorporated community within Lake County. History In 1838, a young boy named Elijah M. Haines (1822–1889) and his family moved from New York City to the Chicago area. In 1836, the young boy purchased a farm in Hainesville. During the winter of 1841–42, Haines taught school in Waukegan, Illinois (then known as Little Fort). In 1846, he surveyed and platted Hainesville. On February 26, 1847, the village incorporation papers were drafted. It is recorded that Elijah Haines met Abraham Lincoln in 1847. The two men met frequently and became well acquainted. It has been said that Lincoln spent the night in Hainesville a few times. In 1848, construction began on the Lake and McHenry Plank Road. By 1851, the road was completed to Squaw Creek just west of Hainesville, and the settlement became the location for one of three toll houses. In 1851, Haines was accepted to the bar, and a year later he moved to Waukegan. In 1859, he was sent to the state legislature where he served eight terms. He was a member of the Illinois Constitutional Convention of 1869-70 and is considered by some historians to have been its most influential member. Hainesville was becoming a thriving village, but the village all but disappeared off the map until recent years. In 1899, the Milwaukee Road railroad expanded into Lake County, providing convenient transportation from the area into Chicago. Local land owner, general store proprietor and Hainesville postmaster George Battershall asked for a large sum of money to build a train station in Hainesville. Milwaukee Road had no other options in Hainesville as the railway entered and exited the village of Hainesville on Battershall's property (essentially everything south of the Plank Road in Hainesville). Amarias M. White, an early settler of what is now Round Lake, knowing that a railroad stop in Round Lake would spark commerce for his area, attracted the railroad company by offering the land for a depot for free. Unfortunately for Hainesville, commerce did start to move away from Hainesville and into Round Lake, as well as neighboring Grayslake. The Hainesville post office closed in 1919. A few years later, the old wooden Hainesville School was destroyed by a tornado. In 1940, a new brick structure