The first skateboard made is impossible to pin down. People invent things all the time. How many of us went into the back yard and nailed contraptions togther out of junk we found.
I predict that there were thousands of people attaching wheels to boards all over the world.
Once rollerskate became available I guarrentee that they were ripped off the boots and nailed to all sorts of things.
I think it is romantic to think that the first skateboard was made by a group of bored surfers. They were probably the first the really get into riding them with any real purpose.
Almost certainly the first skateboard for sale was bred from these surfers.
Even though the inventors of the world may have come up with the same ideas in many different places. The surfing style was what really powered the transformation from a board with wheels into a "sidewalk surfer" or "skateboard". Which was meant for surfing the sidewalks and streets.
Makaha designed the first professional boards in 1963(ref The Concrete Wave). If you are looking to mark the first real skateboard then that would probably be it.
This skateboard had a special deck, trucks and wheel made directly for the purpose of skateboarding. This was a big risk to take. Making all of these parts just for skateboarding would not be cheap. I tip my hat to those who took the risk and started something really great.
It took almost 50 years of skateboard history for the technology to catch up and make skateboarding what it is today. Innovations in tricks and equipment happened bit by bit. These pioneers who made the first production skateboard played a huge roll in that. Thanks!
To see how we got from rollerskates and 2x4's to sidewalk surfers to modern street skating check out my skateboard history page.