The first steel coasters apeared in the late 19th Century. The track was hardened steel, which is relatively brittle as a coaster construction material. These coasters needed a large number of supports (both cross ties and ground) and could never gain large sizes due to the amount of metal required.
This all changed with the development of tubular steel. A track made of tubular steel has a huge strength to weight ration and has allowed for the 400+ feet modern coasters we see today.
The Original
Arrow - Mattehorn Bobsleds
This Disneyland coaster was the first operating steel-tubular coaster in the world. This coaster showed that steel was the way of the future, exhibiting that the new steel tubular track (circular steel track) was very strong, allowing for a smoother coaster as well as a more unique layout.
Variations
Schwarzkopf Coasters
Anton Schwarzkopf and Werner Stengel began making steel rollercoasters in 1964. Schwarzkopf went on to become the leading manufacturer of steel coasters throughout the following decades.
Pinfari Coasters
Pinfari made their first steel coaster in 1966. They continue to make a wide variety of traditional coasters for fairgrounds and small amusement parks, all compact and usually portable..