LaSalle was an American brand of luxury automobiles manufactured and marketed, as a separate brand, by General Motors' Cadillac division from 1927 through 1940. Alfred P. Sloan, GM's Chairman of the Board, developed the concept for four new GM marques - LaSalle, Marquette, Viking and Pontiac - paired with already established brands to fill price gaps he perceived in the General Motors product portfolio. Sloan created LaSalle as a companion marque for Cadillac. LaSalle automobiles were manufactured by Cadillac, but were priced lower than Cadillac-branded automobiles, were shorter, and were marketed as the second-most prestigious marque in the General Motors portfolio. LaSalle's were titled as LaSalle's, and not as Cadillacs. Like Cadillac - named after Antoine de la Mothe Cadillac - the LaSalle brand name was based on that of another French explorer, Rene-Robert Cavelier, Sieur de La Salle.
In its final years, the LaSalle Series 39-50 was once again more Cadillac-like in its appearance and details and was essentially identical to the Cadillac Series 61. The narrow radiator grille opening was retained and was flanked by additional side grille work which aided in heat dissipation from the engine. Headlights, which had moved down and been secured to the body between the grille and the fender, were again attached to the radiator shell. LaSalle also added a sunroof, marketed as the "Sunshine Turret Top". Sales climbed from 15,501 in 1938 to 23,028 in 1939.
The final 1940 LaSalle's were introduced in October 1939 with a full array of semi-custom body styles, as it had in its first year, including a convertible sedan. Earl oversaw this redesign. The LaSalle emerged with a smooth-flowing design; its thin radiator flanked by a series of thin chrome slots. In its final year, sales of the LaSalle reached the second-highest level ever at 24,133. In addition to the Series 40-50, there was also the lower, wider Series 40-52 Special using General Motors' new "Torpedo"-style body