Background
Imperialism occurs when a strong nation takes over a weaker nation or region and dominates its economic, political, or cultural life. Beginning in the 15th century and extending all the way through the 19th century, European nations competed for colonies across the globe.  These colonies were exploited for their raw materials, and used as new markets for European goods.  Europeans had little regard for most of the indigenous peoples of these areas, and as a result, there was great loss of life and culture.

Old Imperialism
Old Imperialism occurs in the 15th through 18th centuries in Africa, India, the Americas, and parts of Asia  The motives were the same for most areas, the establishment of lucrative trade routes.  Various European countries dominated these trades routes and one time or another, and a some countries, such as Great Britain and Spain, came to dominate entire countries. 

New Imperialism
New Imperialism was practiced by European nations and Japan throughout the 1800s and early 1900s. In every case, a nation would experience industrialization prior to practicing imperialism on a foreign nation or region. This is due to the nearly insatiable demand for cheap raw materials and the need for markets to buy manufactured goods.

Industrial Roots: Abundant raw materials and vast markets are needed in order to maintain an industrialized economy. Raw materials such as iron and cotton can be turned into products such as steel and textiles. Finally, these products need to be sold to a market in order to realize a profit.

The forces of industrialization caused nations to begin looking outside of their borders for cheaper and more abundant raw materials. Foreign populations were also viewed as vast markets where goods produced in domestic factories could be sold.