1991: Inspired by the success of the Sunraycer, Hughes division convinces GM to work on an electric passenger car. The result, the lead-acid battery-powered Impact, debuts at the Los Angeles auto show.
1992: Recession puts a hold on development of production version of Impact, but behind-the-scenes research continues, including work on nickel-metal-hydride batteries.
1996: The Impact reaches production as the lease-only EV1. The lead-acid battery pack provides a range of 70 to 100 miles.
1999: Subsidiary Allison Transmission develops Two-Mode hybrid technology for use in buses.
1999: The EV1 gets nickel-metal-hydride batteries, boosting range to between 100 and 140 miles.
1999: GM works with Toyota on hybrid technology but decides that, with gas hovering around $1 a gallon, there's little potential for consumer sales.
2003: The EV1 program ends. GM repossesses -- and crushes -- cars from lessees. GM publicly focuses on hydrogen fuel-cell technology, but the car-electronics team from Hughes, now incorporated into GM, continues work on battery propulsion.
2006: Filled with Prius envy, GM officially sets to work on a mainstream electric car.
2006: Tesla Motors announces that it will produce an electric sports car, spurring GM vice chairman Bob Lutz to emphatically bless skunk works to cobble together Volt prototypes.
2007: Chevrolet Volt concept car debuts at Detroit auto show. GM promises a production version by 2010.
2008: A scaled-down version of the Two-Mode powertrain, developed with Daimler-Benz, Chrysler, and BMW, debuts in Chevrolet Tahoe and GMC Yukon and is named Automobile Magazine's 2008 Technology of the Year.
2009: Promised Two-Mode version of the Saturn Vue dies with the brand. The Volt's control systems are heavily inspired by learnings from the Two-Mode vehicles.
November 2010: First production Volt rolls off assembly line in Detroit. - David Zenlea