The Illinois State Capitol houses the executive and legislative branches of Illinois' state government.  The current building is the sixth to serve as the state's capitol.

The structure is in the architectural style of the French Renaissance Ground was broken on the building in 1869, and took twenty-years to complete. It sits on a nine-acre plot of land.

The silvery dome is covered in zinc, which does not weather. The dome is 92.5-feet in diameter. At a total height of 361-feet, the Illinois State Capitol is the tallest non-skyscraper capitol building in the United States. In fact, it even exceeds the height of the U.S. Capitol building in Washington, D.C.

The building is in the shape of a Latin cross and is aligned to the major compass directions.

The Illinois State Capitol is open to the public and guided tours are available.