1940: Oldsmobile offers the first fully automatic transmission, the four-speed Hydramatic as a $47 extra. GM produces its 25-millionth U.S.-made car. U.S. President Franklin Delano Roosevelt names GM President William Knudson chairman of the Office of Production Management, helping America gear up for World War II.

1942: GM shifts all its production to the wartime effort.

March 18, 1947: Durant dies, virtually penniless at age 85. His last venture had been a bowling alley in Flint.

1948: Cadillac line and Olds 98 launch early in the '48 calendar year with GM's first all-new postwar styling. The Cadillacs are distinguished for their relatively subtle tailfins, inspired by the Lockheed P-38 Lightning' twin vertical stabilizers.

1949: Cadillac, Motor Trend's first Car of the Year, and Oldsmobile come with GM's first high-compression, overhead valve V-8s, of 331 and 303.7 cubic-inches, respectively. Olds Rocket 88 inspires Ike Turner to write what some consider the first ever rock 'n roll song.

1949-50: The Autorama, in New York and Boston the first year, and New York the second, is GM's first big display of post-war, mid-century exuberance.

1951: GM LeSabre and Buick XP-300 dream cars are unveiled.

1952: Cadillac, Buick and Olds offer optional power steering. Power brakes are offered on the three the following year.

1953: The Motorama is the mid-century future, GM-style, with dream car and dream home/kitchen (Frigidaire, remember) displays. Between now and 1961, Motoramas show (un-branded) Firebirds I, II & III, the Cadillac LeMans, LaSalle II, Buick Wildcats I, II & III and Centurion, Olds F-88, Pontiac Bonneville-Special and Chevrolet Corvette, the last of which goes into limited production in Flint, Michigan, in '53.

1955: Chevy Bel Air features optional small-block V-8, the division's first eight-cylinder engine in 37 years. Buick and Oldsmobile pioneer the four-door hardtop.

1957: Chevrolets Corvette and Bel Air, and Pontiac Bonneville are GM's first cars offered with fuel injection.

1959: models have all-new, lower-wider-longer bodies rushed to market to battle the 1957 Chrysler Corporation Forward Look. The '59 Cadillac becomes an icon with the biggest tailfins ever.