Final answer:
The progressive dates on the Manifest Destiny map are significant as they show the temporal progression of U.S. territorial expansion and embody the continuation of Manifest Destiny beliefs into the 1890s. John Gast's painting 'American Progress' symbolizes the spread of American values and technology, further reinforcing the ideology's divine sanction. Expansion continued into the 19th century, transitioning from continental to overseas imperialism.
Step-by-step explanation:
The important aspect of the progressive dates on the Manifest Destiny map is that they illustrate the temporal progression and expansion of the United States territory from the East to the West Coast. In the 1890s, American expansion was indeed a continuation of the ideology of Manifest Destiny that became prominent in the 1840s, suggesting that the United States was destined to expand its democratic institutions across the continent. The concept was further embedded in the culture via artifacts like John Gast's painting American Progress (1872), depicting a figure of Columbia, which personified the nation, advancing westward and spreading light, symbolizing enlightenment and progress. This imagery reinforced the belief in American exceptionalism and the notion that such expansion was divinely sanctioned and inevitable.
John O'Sullivan's idea of Manifest Destiny implied not only territorial growth but also the spread of American values and institutions. In Gast's painting, technological advancements such as the telegraph and the dissemination of knowledge, represented by the school book, are portrayed as civilizing forces amidst the untamed wilderness. The departure of Indigenous peoples and wildlife before Columbia's advance highlights the discordant impacts of this progress and the ideology's disregard for the original inhabitants of the land.
By the end of the 19th century, the United States had not only expanded to the Pacific coast but had also begun to project its power beyond, embracing an imperialistic stance in places like the Philippines, Cuba, and Puerto Rico. Thus, the progression of these dates showcases the ongoing American quest for expansion and the embedded belief in the righteousness of their national destiny, which, by the 1890s, transitioned from continental aspirations to overseas ambitions.