Vandalia State House State Historic Site preserves Illinois’s fourth capitol building, erected in 1836 after earlier statehouses at Kaskaskia and Vandalia were abandoned, destroyed, or deemed unsafe. Built in brick in about four months for $16,000, it is the oldest surviving Illinois capitol. The building stands at an important turning point in state history: while serving in the Illinois General Assembly there, Abraham Lincoln participated in the successful effort to move the capital to Springfield in 1837. Afterward it served Fayette County as a courthouse until 1933, later gaining preservation as a historic site and museum focused on Illinois’s early government and Lincoln’s emerging political world.