Spring Hill Manufacturing is a General Motors factory in Spring Hill, Tennessee. The plant currently includes vehicle assembly (Cadillac Lyriq, Cadillac XT5, Cadillac XT6, and GMC Acadia) as well as powertrain, stamping and molding operations. The plant originally operated as the sole manufacturing facility for Saturn Corporation. History On January 7, 1985, Saturn Corporation was formed as a subsidiary of General Motors to compete with Japanese imports, and shortly thereafter, began searching for a site for a manufacturing facility. Then-governor Lamar Alexander began encouraging GM to locate the plant in Tennessee. The site in Spring Hill was officially announced on July 26, 1985. At the time, Spring Hill was a predominantly agricultural community with a population of about 1,000. A payment in lieu of taxes agreement was negotiated with the state in September 1985, and that same month the Tennessee Department of Transportation announced plans to construct State Route 396 (Saturn Parkway), a long controlled access highway that connects the plant to Interstate 65, at a cost of $29.3 million. This was completed in 1989. Preliminary site work for the plant began in May 1986, and construction activities began two months later. The plant began operation on July 31, 1990, when the first vehicle was produced. The decision to locate one factory as the source of Saturn vehicles was based on a tradition GM was founded on in 1909 with the core brands that came together to form GM. Chevrolet, Pontiac, Oldsmobile, Buick and Cadillac each had main factories where the cars originated from, then in 1933 branch assembly plants were established in major American cities and the branch assembly locations would receive knock-down kits from the main plants and locally assemble GM products to meet demand. The main facilities were Flint, Michigan for both Buick and Chevrolet; Oldsmobile at Lansing, Michigan; Pontiac at Pontiac, Michigan; and Cadillac at Detroit, Michigan. The approach for Saturn was to have one dedicated location where vehicles originated from one location as in the past with the legacy brands. Manufacturing continued through March 2004 as the sole assembly plant overseen by the Saturn subsidiary. After the United Auto Workers ratified a new contract in March 2004, the plant became part of General Motors, but Saturn-only manufacturing lines continued until March 2007. The facility includes a four-cylinder engine assembly plant, auto assembly plant, paint and plastics plant, a Saturn parts warehouse, and a visitors center.