The Chrysler Corporation introduced the Imperial as a separate luxury make and division in 1955.
 LeBaron was designated the top of the line Imperial models from 1956 through 1975.
These cars were Imperials and did not include the "Chrysler" nameplate.
Vehicles branded "LeBaron" were the top model of the Imperial line, followed by the mid-line "Crown" and a short-lived nameless base model ("Custom" from 1960–63); with "Southampton" being a sub-designation applied to all pillarless hardtops.

The Imperial LeBarons were made to compete directly with competitor's luxury brands that included Continental, Cadillac, and Packard, as was the case during the 1930s.

The last Imperial model was assembled in June 1975, the discontinuation resulting from dwindling sales due to a recession, the effects of the 1970s energy crisis, and the United States Congress having passed the Energy Policy and Conservation Act, establishing Corporate Average Fuel Economy standards.
The Chrysler Corporation introduced the Imperial as a separate luxury make and division in 1955.  LeBaron was designated the top of the line Imperial models from 1956 through 1975. These cars were Imperials and did not include the "Chrysler" nameplate. Vehicles branded "LeBaron" were the top model of the Imperial line, followed by the mid-line "Crown" and a short-lived nameless base model ("Custom" from 1960–63); with "Southampton" being a sub-designation applied to all pillarless hardtops.
The Imperial LeBarons were made to compete directly with competitor's luxury brands that included Continental, Cadillac, and Packard, as was the case during the 1930s.
The last Imperial model was assembled in June 1975, the discontinuation resulting from dwindling sales due to a recession, the effects of the 1970s energy crisis, and the United States Congress having passed the Energy Policy and Conservation Act, establishing Corporate Average Fuel Economy standards.
Chrysler LeBaron