The steam engine was the most important and far reaching development of the Industrial Revolution which led to monumental progress for human society.
The steam engine was perfected (not invented) by James Watt at the University of Glasgow, Scotland. It was originally used in coal mines but its effects soon became far reaching. It replaced the water wheel in flour mills, powered machinery in the early textile mills of Britain, and was even used to power equipment which crushed sugar cane for the production of refined sugar. In the iron and later steel industries, steam was used to operate bellows for blast furnaces which led to larger production of these metals. British production of iron had been 17000 tons in 1788 when furnaces fueled by charcoal were used. By 1806, that number had increased to 260,000 tons, and iron became a staple of the building industry.
The steam engines greatest benefit came in transportation of both goods and people. The steam engine led to the development of the railroad, which allowed goods and people to be moved overland without the need for navigable rivers and streams. The railroad allowed for greater production of manufactured goods as the cost of transporting them was reduced dramatically. This led to the enhancement of the factory system and marked the end of the old putting out system of manufacture. As an incidental side effect, the factory system and the development of the urban worker as a class of society was also the result of the invention of the steam engine.