Answer the following Q with stream of consciousness. Passage: Douglas Park is a large Chicago Park District park that serves as a cultural and community center on the West Side of Chicago, Illinois. It is named after the U.S. Senator Stephen A. Douglas. Originally named South Park, its 173 acres (0.70 km) are in the North Lawndale community area with an official address of 1401 S. Sacramento Drive.

Question: Based on this passage, who is douglas park in chicago named after?
To answer the above question, the relevant sentence is: It is named after the U.S. Senator Stephen A. Douglas. Therefore, the final answer is the U.S. Senator Stephen A. Douglas.