Inventor: George Stephenson

Before the creation of steam locomotive technology, railroads were occupied by coaches that were pulled by horses.  Some unsuccessful attempts to improve this system included using a horse on a treadmill to move the carriage wheels, and creating a steam powered machine with legs similar to horses’ legs. 
George Stephenson of England made the first successful steam powered locomotive in 1814.  This used the steam engine, a prior technological innovation. The steam engine works by using hot, pressurized steam to produce mechanical energy, after which the steam is cooled and condensed.  At this time, all engine production had to be done by hand. The first locomotive that he created was able to pull eight wagons weighing thirty tons total at a speed of four miles an hour. He continued to produce more locomotives, with each one being more powerful than the previous.
The first locomotive that was implemented in America was the Stourbridge Lion in 1829.  However it was too heavy for the track and therefore unusable. Six weeks later, Peter Cooper built the Tom Thumb, the first locomotive to carry passengers in the US. Finally in 1830, the first completely American made train with a regular passenger transporting service was made.  The high point of the age of railroad transportation was when the Union Pacific and Central Pacific railroads were joined at Promontory Summit in 1869 creating the first transcontinental railroad.
The steam locomotive soon became one of the most popular and effective ways of long distance passenger and goods transportation.  It led to a large increase in westward expansion and more efficient domestic trade.  One of its strongest benefits was that it was able to transport large, heavy loads across a long distance, which was not possible when it was horses pulling the load.  Even today, some of our largest freight transports are accomplished using trains. 

Pictures from <http://carsandtrains.com/ironroad/dsn/dsn02.html>

SOURCES:

Brown, William H.  The History of the First Locomotives In America,  New York, Appleton and Company, 1871

• This website provides a basic description of the invention of the steam locomotive

Houk, Randy. “Railroad History: Important milestones in English and American railway development”  21 Mar 2003 <http://www.sdrm.org/history/timeline/> 

• This website gives a timeline of important events in railroad and locomotive history