Kodachrome was invented by two concert grade musicians: Mannes and Godowski, one of whom was George Gershwin's brother in law, with the backing of Kodak. George Eastman wasn't really keen on color (Lumiere slides are very grainy) so someone lower on the food chain at Rochester backed them. They started about 1914 and by the early 1920s, Kodak took notice and invited them up to Rochester.

Solution temperatures are extremely critical, and even more so the timing of each step in the development process. There weren't good photographic timers in that day (1914-1935), so they would whistle a Bach fugue and change steps at particular bars. It took until about 1936 before they got the process to the stage where it would be commercially viable. At the time Kodak was on the verge of marketing a two-color process, but there were some last minute snafus. Thank goodness for that because Kodachrome is a far better product. The other scientists at Rochester thought they were a bit off, what with all that constant whistling in the darkroom, and took to calling them Man and God.

Kodachrome is a color additive process in that the couplers (color dyes) are added to the film during processing. They dyes are aniline, which is carcinogenic, and many of the chemicals used are extremely poisonous. The early emulsion speeds were 8 and 10, which became 25 (daylight type) in the mid to late 1950s.

Kodachrome has the reputation of being the most faithful at recording colors with the most stable dyes, so at one time all the museums in the world used it for photographic records of their paintings.

Ektachrome uses insoluble color couplers, meaning the dyes are in the film when you buy it.

I always preferred Kodachrome because of Ektachrome's bluish cast. The Ek slides I took of the P&W in the late 1960s are now mostly green. On the other hand, pro Ek, had better dyes. In the mid 1960s a friend showed me several 20 year old 4x5 color slides of people like Edward Weston which still had great color.

With digital, the colors depend on the dyes (toner, etc.) your using and the color balance you select with your photo program, not the computer file (the png format is less lossy than jpg).

Yes, it's sad to see it go away, but I stopped using it (35mm and 120) about 10-12 years ago.