Mercury was its own division at Ford until 1945 when it was combined with Lincoln into the Lincoln-Mercury Division, with Ford hoping the brand would be known as a "junior Lincoln", rather than an upmarket Ford. In 1949, Mercury introduced the first of its "new look", integrated bodies, at the same time that Ford and Lincoln also changed styling radically. Again in 1952, Mercury offered a further modernization in its look. In 1958, the Lincoln-Mercury Division and the ill-fated Edsel brand were joined into the Mercury-Edsel-Lincoln Division; with the demise of Edsel in 1960, it has been in the Lincoln-Mercury Division ever since.

Mercury, like the defunct Edsel, was created from scratch, rather than being a takeover of an existing company like Lincoln. Mercury's heyday was in the 1950s, when its formula of stretching and lowering existing Ford platforms was very successful. The marque has changed several times throughout its history. During the 1940s and 1950s, the make moved between as a "gussied up" Ford, to a "junior Lincoln" and even to having its own body designs. From the late 1950s, through the 1960s and early 1970s, Mercury began to distance itself from Ford and offered several different looking models such as the Turnpike Cruiser, Park Lane, Cougar and Marquis. During Ford Division's "Total Performance" era in the early 1960s, Mercury produced some equivalent models, such as the full-size S-55 Marauders, which shared the same body styles and mechanics as the Ford Galaxie 500/XL sports models. These big Mercurys were somewhat successful in racing. But in the late 1970s to the early 1980s the brand was joined at the hip with Ford again and its image suffered as a result.

Mercury sales peaked in 1978 at 580,000 and again in 1993 at over 480,000. Since then, sales have declined by more than half to roughly 200,000 annually. In the mid-1990s the Mercury car brand received some very good free PR when country music star Alan Jackson scored a hit with a cover of K.C. Douglas' "Mercury Blues", a song which heaps complimentary praise on their vehicle range.

Mercury has had a few unique models not shared with domestic Fords, but usually related to other vehicles sold domestically or world wide. These include the Capri convertible (which shared some parts with the Mazda 323 but wasn't nearly as popular, ending production in Australia in 1993), Mercury Tracer (later shared with the Escort, but was a Mexican-built version of the Mazda 323 hatchback in the late 1980s and in '90), Mercury Villager (a name used earlier as a luxury station wagon, but from 1993-2003, it was a minivan shared with Nissan, which sold its version as the Quest and built the drivetrain for both versions), Mercury Cougar (1999-2002, based on the Ford Contour/Mercury Mystique/Ford Mondeo platform but sporting a 2-door, hatchback only bodystyle with sharp styling not shared with the more mundane sedan versions), and the German built Mercury Capri in the '70s (before that model moved to the Ford Fox platform as a twin to Ford Mustang). In 1971, dealers also sold the De Tomaso Pantera exotic sports car, with a Ford V-8.