1939-1951 Cadillac Series 60, 61, 63
These early Cadillac Series can be confusing until you know the underlying reasons for the shuffling. All of General Motors was built upon a tiered division of cars. Each division from the entry-level Chevrolet through Pontiac, Oldsmobile, Buick, Lasalle, and at the top Cadillac, was thought to cover all price points for potential car buyers, so that theoretically GM could capture a buyer for life. In the 1930s each division juggled lineups around to cover their segment of the market, and when they saw a gap they tried to fill it. That explains some of the confusion in Series comings and goings.
The other reason was that once GM decided to kill Lasalle in 1940, it left some holes for Buick, positioned below Lasalle, and Cadillac above Lasalle, to fill. This resulted in a somewhat bewildering shuffle of Series names and sometimes odd product meant to cover all bases.
First appearing in 1936 the Cadillac Series 60 was meant to bridge the gap between the Lasalle and Cadillac Series 70. The Lasalle was the “baby Cadillac” division positioned between Buick and Cadillac price-wise. Cadillac manager Nicholas Dreystadt believed a large enough gap existed between the higher-priced Lasalle, and lowest-priced Cadillac, that Cadillac needed to fill the hole with the Series 60. The Series 60 was based off of the GM B-body platform shared with Oldsmobile, Buick and Lasalle.
The Series 60 ran through 1938, replaced by the Series 61 in 1939.
The Series 61 replaced the 60 Series in 1939. Available as a club coupe or sedan on the 126-inch B-body wheelbase, it lasted this one year, then was replaced by the Series 62 in 1940, but was revived in 1941. In 1942 automobile production was halted for WWII, and resumed in 1945 as 1946 models. The Series 61 was included in the Cadillac lineup.
In 1948 when the new Cadillac C-body was introduced, it included the Series 61, which up to this point was on the smaller B-body chassis. Aligned so close to the Series 62, which also was based on the C-body, there was not enough differentiation to justify both series, and so the Series 61 was moved back to the smaller B-body in 1950.
Without enough sales to justify continuation, the Series 61 line ran through 1951 and was discontinued.
Plans had already progressed for a 1941 Lasalle when it was decided to discontinue it after 1940. The Series 63 was basically the intended 1941 Lasalle turned into a Cadillac. Available for this one year, sales reached 5,030 units. By 1942 it was determined that Series 61 could break down options and price points to cover what the separate Series 63 represented, eliminating the confusion and added expense of marketing this separate series.