Cook County

Cook County is a large county in Illinois that includes the city of Chicago and surrounding communities. It serves as a regional government hub, providing services like courts, public health, and transportation. With over 5.2 million residents, it is one of the most populous counties in the United States. Cook County also manages the county jail system, runs the public hospital system, and supports local law enforcement. Its government helps organize regional planning and economic development, making it a central administrative area for urban and suburban life in northeastern Illinois.