The growth of the state of Illinois during Lincoln's presidency in the 1800s demanded more office space than the Old State Capitol allowed. Today, the current Capitol Building (opened in 1877) is the center of state government and houses the offices of the Governor and state officers, as well as the House of Representatives and Senate Chambers. Visitors can watch Illinois politics in action when the legislature is in session. Both the old and current State Capitols are open to the public