Flint, Michigan is a city which previously relied on its automotive industry, and still does to an extent. Over the past several decades, General Motors plants in Genesee County have experienced re-namings, management shifts, openings, closures, reopenings, and spinoffs. Plant history Durant-Dort Factory One General Motors traces its roots to the Durant-Dort Carriage Company of Flint named after William C. Durant and Josiah Dallas Dort, and purchased the original Durant-Dort factory (built in 1880 as a woolen mill) on Water Street in May 2013 (and the Durant-Dort office, a National Historic Landmark across the street, as well). The company will take over responsibility for maintenance from the Flint Historical Foundation. Buick Motor Division Division HQ and Assembly, Engine, Parts Plants/Buick City/Powertrain Flint North On Hamilton Avenue, the oldest buildings opened in 1908. This was the largest GM complex in the world. Buick originally opened in Flint on West Kearsley Street; this plant was repurposed as the first Chevrolet factory after the Hamilton Avenue site opened. In 1983 Buick announced plans for Buick City (inspired by Toyota's "Toyota City" plant), which would combine Buick's assembly and Fisher #1's bodybuilding operations. The production of rear-wheel drive cars at Buick's Hamilton Avenue plant ended. After gutting the interior, installing robots (and other retooling), and the construction of a new body shop and just-in-time delivery docks, Buick City began building front-wheel drive vehicles in 1985. Buick Motor Division became a marketing and public-relations entity in 1984, when the Buick-Oldsmobile-Cadillac Group (BOC) was created and took over engineering and assembly control from Buick, Oldsmobile, Cadillac and the GM Assembly Division. GM created the Flint Automotive Division to manage BOC's activities in Genesee County, which included the former Buick factories and engineering. BOC dissolved in 1992, and eventually its functions were transferred to the Cadillac/Luxury Car Division (not to be confused with the Cadillac Motor Car Division, the traditional Cadillac operation). Buick City closed in June 1999. It (and other former Buick buildings not technically part of Buick City) was demolished from 2001 to 2003. The Buick Motor Division administration moved to Detroit in 1998. The 1960s-era former Buick world headquarters, after briefly housing EDS workers until 2003, was demolished in 2006. The adjacent former Buick transmission, transmission-parts, engine-assembly and engine-parts plants (GM Powertrain and Flint North) closed by December 2010. AC Spark Plug Division/Delphi Corporation Industrial Avenue plant Built before 1912, it replaced the original