This engine was invented by James Watt, who worked on it between 1763 and 1776. It's not the first steam engine ever to be created - the design is based on something called the Newcomen engine, which dates back to 1712. However, the Watt engine is widely considered the first design that was actually practical.
Watt's engine had two advantages over other engines of the day - it operated at a low pressure - meaning that there would be fewer boiler explosions when it was used (and boiler explosions could be so annoying) - and didn't waste coal - which, like gasoline today, was expensive. In fact, his design was so good it wouldn't be significantly improved on for another hundred years.