New Imperialism refers to the colonial expansion adopted by Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

's powers and, later, Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 and the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, during the 19th and early 20th centuries; expansion took place from the French conquest of Algeria

French conquest of Algeria

The French conquest of Algeria took place between 1830 and 1847. Using an 1827 diplomatic slight by Hussein Dey, the ruler of the Ottoman Regency of Algiers, against its consul as a pretext, France invaded and quickly seized Algiers in 1830, and rapidly took control of other coastal communities...

 until World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

: approximately 1830 to 1914. The period is distinguished by an unprecedented pursuit of overseas territorial acquisitions.

The qualifier "new" is to contrast with the earlier wave of European colonization from the 15th to early 19th centuries.
The American Revolution

American Revolution

The American Revolution was the political upheaval during the last half of the 18th century in which thirteen colonies in North America joined together to break free from the British Empire, combining to become the United States of America...

 and the collapse of the Spanish Empire

Spanish Empire

The Spanish Empire comprised territories and colonies administered directly by Spain in Europe, in America, Africa, Asia and Oceania. It originated during the Age of Exploration and was therefore one of the first global empires. At the time of Habsburgs, Spain reached the peak of its world power....

 in the early 1810–20s, following the revolutions in the viceroyalties of New Spain, New Granada

Viceroyalty of New Granada

The Viceroyalty of New Granada was the name given on 27 May 1717, to a Spanish colonial jurisdiction in northern South America, corresponding mainly to modern Colombia, Ecuador, Panama, and Venezuela. The territory corresponding to Panama was incorporated later in 1739...

, Peru

Viceroyalty of Peru

Created in 1542, the Viceroyalty of Peru was a Spanish colonial administrative district that originally contained most of Spanish-ruled South America, governed from the capital of Lima...

, and the Rio de la Plata

Viceroyalty of the Río de la Plata

The Viceroyalty of the Río de la Plata, , was the last and most short-lived Viceroyalty of the Spanish Empire in America.The Viceroyalty was established in 1776 out of several former Viceroyalty of Perú dependencies that mainly extended over the Río de la Plata basin, roughly the present day...

 ended the first era of European imperialism.