High Quality Content by WIKIPEDIA articles! New Imperialism refers to the colonial expansion adopted by Europe`s powers, the United States and, later, Japan during the 19th and early 20th centuries; expansion took place from the French conquest of Algeria until World War I: approximately 1830 to 1914. The period is distinguished by an unprecedented pursuit of overseas territorial acquisitions. At this time, countries focused on building their empire with new technological advances and developments, making their country bigger through conquest, and exploiting their resources.