The Henry J was the idea of Henry J. Kaiser, who sought to increase sales of his Kaiser automotive line by adding a car that could be built inexpensively and thus affordable for the average American in the same vein that Henry Ford produced the Model T. The goal was to attract "less affluent buyers who could only afford a used car" and the attempt became a pioneering American compact car. To accomplish this, the Henry J was designed to carry the fewest possible components, and built from the fewest number of parts. To save body stamping costs, early Henry J's did not have rear trunk lids; owners had to access the trunk by folding down the rear seat. Another cost-saving measure was to offer the car only as a two-door sedan with fixed rear windows. Also lacking in the basic version were glove compartment, armrests, passenger-side inside sun visor and flow-through ventilation.
Power for the Henry J was delivered by a 134.2 cu in (2.2 L) four-cylinder 68 hp engine. Later models were available with a 161 cu in (2.6 L) L-head six-cylinder engine producing 80 hp. The engines were supplied by Willys-Overland; the four-cylinder engine was the same engine used in the CJ-3A series Jeeps, with only slight modifications to component parts; the block and internal components were interchangeable with the CJ-3A engine. The Henry J production provided a substantial revenue source for Willys-Overland. This standard engine could achieve up to 35 mpg when driven conservatively.