The first patented roller skate was introduced in 1760 by Belgian inventor John Joseph Merlin. His roller skate wasn’t much more than an ice skate with wheels where the blade goes. They were hard to steer and hard to stop because they didn’t have brakes and as such were not very popular.
In 1863, James Plimpton from Massachusetts invented the “rocking” skate and used a four-wheel configuration for stability, and independent axles that turned by pressing to one side of the skate or the other when the skater wants to create an edge. This was a vast improvement on the Merlin design that was easier to use and drove the huge popularity roller skating, dubbed “rinkomania” in the 1860s and 1870s, which spread to Europe and around the world, and continued through the 1930s. The Plimpton skate is still used today.