When did activities occur that demonstrate Americans' belief in Manifest Destiny?

The activities that most demonstrated Americans' belief in Manifest Destiny occurred during the 19th century, while thousands of settlers moved west and displaced thousands of natives. 

Explanation:

The activities that demonstrate American's belief in imperialism happened in the nineteenth century. The term "manifest destiny" originated within the decade. it had been the wide held belief that the America enlargement was excusable and inevitable.

In the nineteenth century, Americans began to manoeuvre west, inflicting the displacement of the many native Americans.