The first mass produced car built on an assembly line was Henry Ford's Model T, right? Wrong. It was actually Ransom Old's Curved Dash Runabout which he mass produced in 1901. Granted, this was a stationary assembly-line whilst Ford's was a moving one. It was still however a great improvement on the somewhat slapdash production techniques that every other manufacturer had used up until then.
Ransom Eli Old was a car industry pioneer who claimed to have built his own first petrol engined car in 1896 and a steam driven one even earlier in 1887. In 1897 he had founded his own car manufacturing company, the Olds Motor Vehicle Company. He sold it to an entrepreneur called Samuel Smith who renamed it the 'Olds Motor Works' but stayed on as general manager and vice president.
The Curved Dash very nearly never saw the light of day except in prototype. Named after it's curved footboard, typical of the carriages drawn by horses, that the new horseless carriages were gradually replacing, it was never really seen by the Olds staff as a serious contender for mass production. It was only one of about a dozen prototypes that were being considered, but a disastrous fire at the works destroyed all the others.
The story has been put about that this is why this particular model was selected, even though it faced competition from steam, petrol and electricity driven prototypes; however the fact was, apparently, that there were already 300 advanced orders for it, so was the claim merely an advertising gimmick? Perish the thought.
And yes it did sell well. At an initial retail price of $650 there were about 600 sold in 1901, around 3000 in 1902 and even more, possibly in excess of 4000, in 1904.
In that year however Olds had to leave the company because of clashes with Smith's son, Frederic, to form another company. Production of the Curved Dash continued until 1907 by which time 19,000 had been built. By 1908 the company was getting into financial difficulties and it was sold to General Motors who only dropped the Oldsmobile brand in 2004 after 96 years of car manufacture.