The Secretary of State is the keeper of the official records, laws, and Great Seal of Illinois. These duties have remained unchanged since Illinois became a U.S. state in 1818. In addition, the Secretary is the custodian of the Illinois State Capitol. The office is also responsible for administering the laws and procedures concerning the registration of corporations, lobbyists, and notaries public.
The Secretary of State performs other duties prescribed by law. The Secretary oversees the state archive and the state library. The State Library houses more than 5,000,000 items, and other informational resources, and oversees a consortium of academic and regional libraries in the state.
By statute, the Illinois Secretary of State is tasked with the duty of issuing licenses to Illinois-registered motor vehicles and their drivers, effectively making the Secretary of State's office the department of motor vehicles, though that phrase is not used in Illinois. Enforcement of these duties has made the Secretary of State's office a key bureau in the enforcement of laws against driving under the influence. Illinois is one of only two states to put the secretary of state in charge of driver services, the other being Michigan.