How does the invention work?
The heat turns water in the engine's boiler into steam. In many locomotives, the steam is then superheated (heated beyond boiling temperature) before being fed into two or more cylinders. In each cylinder, the steam pushes against a disc called a piston. Special valves control the flow of steam, causing it to press against one side of the piston and then the other. This alternating pressure creates a reciprocating (back-and-forth) motion. See Steam engine (Reciprocating steam engines).
Where did the invention occur?
The earliest locomotives were invented and developed in the United Kingdom.
When did the invention occur?
From the 1830's until the 1950's, steam locomotives pulled nearly all railroad trains
Why was there a need for this invention?
To transport goods and coal. They were also used to get people place to place.
Why is this invention important in history?
Because then we wouldn't have a fast way to transport coal and other industrial goods.