The site alteredusa.com has an interesting article about the origins of the electric skateboard and its history, following the 1997 ban of the gasoline-powered Motoboard (the first mass-produced motorized skateboard), due to noise and pollution.
The history of the electric skateboard starts with mr. Louie Finkle (aka Electric Louie), who filed his patent in 1999:
In the late 1990’s, Louie Finkle (aka Electric Louie) invented and patented the wireless electric skateboard. From handmade electronics, a 100% original brushed motor design, to the world’s first ‘torsion’ trucks – Louie’s first boards were truly revolutionary. Back then, most things had cords, and lithium battery technology was still in its infancy. Louie combined wireless technology, speed and power with stability and reliability. Exkate was born. The only downside? Price. Back then, an X24 set you back around $1200.
However, according to Wikipedia, it wasn’t until 2004-2006 that electric motors and batteries were available with sufficient torque and efficiency to power boards effectively.
The benchmark board of today is arguably Boosted Boards. Founded by Sanjay Dastoor, John Ulmen, and Matthew Tran in 2012. The Boosted company started a Kickstarter campaign promising a premium electric skateboard called the “Boosted Board”.
Importantly, famous youtuber Casey Neistat rides Boosted, not only promoting the company, but also spreading the gospel about esk8ing as such.