The last American convertible of an era, a Cadillac, comes off the line in 1976

A white Fleetwood Eldorado convertible, the last American-made soft-top car at the time, rolled off the assembly line at GM's Cadillac assembly plant in Detroit on April 21, 1976, ending a tradition that began in 1916.

The American-built convertible had joined the running board and rumble seat in the auto industry's scrapyard — for a time.

American Motors stopped convertible production in 1968, followed by Chrysler in 1971, Ford in 1973 and most of General Motors in 1975.

The last 200 Fleetwood Eldorado convertibles produced were all the same: white with white tops, white wheel covers, white leather seat trim with red piping, red carpeting and matching instrument panel, and red and blue hood accent stripes to mark America's bicentennial.

Pricing started at $11,049 and options pushed the tab closer to $13,000, though many dealers fetched considerably more for what was billed as a collector's item.

The last Eldorado convertible produced was kept by Cadillac.

Cadillac produced its first convertible in 1916, and there had been an open-air car in the brand's U.S. lineup ever since. But convertible demand, which peaked in the years following World War II, began to decline in the mid-1960s.

Cadillac's convertible output peaked from 1963 to 1966, when it produced some 20,000 convertibles a year, with one out of every eight customers driving one.

Edward Kennard, head of Cadillac in 1976, said convertibles had been going out of favor with U.S. consumers because of improved styling of hard-top coupes, wider use of air conditioning and rising highway speeds. Some analysts also blamed air pollution and government safety regulations for the convetible's demise.

Chrysler Corp., spurred by Chairman Lee Iacocca, began production once again of soft-top cars with the 1982 Chrysler LeBaron. Ford then resurrected the convertible Mustang, and GM responded with the convertible Pontiac Sunbird.

General Motors was later sued by owners of the 1976 Eldorado when it began selling the 1984 Cadillac Eldorado convertible.