In the summer of 1966, Volvo introduced the 144 as the successor to their popular 120 line, and introduced the company’s identifying boxy aesthetic in the process. Volvo re-imagined nearly every aspect of the car, including its name. In Volvo-speak, the 144 designation is a first series, four-cylinder, four-door car.

And whereas the 120 featured soft, rounded edges nearly everywhere, the 144 wore a body more straight up and down, with large flat surfaces, hard edges, and sharp corners. Aside from the car’s boxy appearance, the car was also very safe, with energy-absorbing crumple zones front and rear and disc brakes on all four wheels—unheard of on most family cars of the era, particularly at the Volvo's $3,000 price point. The system utilized dual circuits, so even if one failed, most of the car's braking capabilities were retained. The car aced U.S. safety regulations.

Underhood, the 144 relied on Volvo's trusty 1.8-liter engine, the B18A, the only major tie to the car's predecessors. The unit produced 75 hp and was mated to a 3-speed automatic or 4-speed manual. In the sporty 144S, the B18B unit benefitted from dual carburetion and higher compression, and output was increased to 90 hp.

The two-door 142 appeared in the early summer of 1967, and the five-door 145 wagon showed up later in the year. For 1968, Volvo replaced the B18 with a larger, more powerful 2-liter engine, dubbed the B20. Sales and production of the already-popular Swede began to climb rapidly—by as much as 70% in the U.K.

Safety innovations continued to make their way into the 140 series. Front seat head rests and rear seat, three-passenger seatbelts became standard in 1969, as did a rear window defroster. Also introduced that year was the 164, which was essentially a 144 with a 6-cylinder car and a fussy nose that deviated from the overall design.

Changes were minimal in 1970, though significant updates arrived in 1971, including a new front grille, which was blacked out and carried Volvo's now-signature diagonal chrome strip. Also new was the M41 4-speed manual transmission, which benefitted from electrical overdrive. It provided shorter throws, which lent the small sedan a more sporting feeling on the road. SU carbs replaced Zenith-Strombergs on the 142S, but most importantly, Volvo introduced Bosch electronic fuel injection—D-Jetronic. The system was found on the new 142E model, which also received a leather interior, and power was rated at 135 hp.

Safety and practicality continued to advance technical development and innovation in the 140, and from 1972 to 1974, Volvo outfitted the cars with larger, adjustable lumbar supports, and a new GL trim appeared featuring a sunroof. Three-point seatbelt harnesses were added for rear outboard passengers, and revised bumpers front and rear appeared (culminating with large safety bumpers in '74). During this same period, Volvo adopted SAE horsepower ratings, which meant that, at least on paper, output ratings of all B20 variants fell dramatically.

Volvo phased out the 140 series as it phased in the car's replacement—the 240, which would carry on the "boxy but good" mantra for another two decades.