The main idea behind the settling of western lands by americans in the early 1800s was known as

the manifest destiny concept.

Explanation:

In the  1800s Americans longed for lands in the American West. they focused on settling at  Ohio River, parts of the Southeast and lands west of the Mississippi River. There were various ways of acquiring the lands which were, purchase from foreign empires, Native American treaties, and war. All these methods were from the concept of Manifest Destiny, which was the idea where people believed that it was inevitable and acceptable for the United States to extend from the Atlantic to the Pacific Oceans.

war never

world war i began in 1914, after the assassination of archduke franz ferdinand, and lasted until 1918. during the conflict, germany, austria-hungary, bulgaria and the ottoman empire (the central powers) fought against great britain, france, russia, italy, romania, japan and the united states (the allied powers). to new military technologies and the horrors of trench warfare, world war i saw unprecedented levels of carnage and destruction. by the time the war was over and the allied powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.

explanation: