Fort Sheridan is a residential neighborhood spread among Lake Forest, Highwood, and Highland Park in Lake County, Illinois, United States. It was originally established as a United States Army Post named after Civil War Cavalry General Philip Sheridan, to honor his services to Chicago. When the main fort was officially closed by the Army on 3 May 1993, the majority of the property was sold by the Department of Defense to commercial land developers. Most of the original housing structures were then refurbished and resold as a residential community. Approximately 90 acres of the southern end of the original post was retained by the Army and now operates as the Sheridan Reserve Center complex.