How did the Manifest Destiny play a role in the development of the United States in the 20th Century?
It's an essay. Why did we start World War I and World War II- to protect ideas of democracy which would relate back to Manifest Destiny? I don't know where to start...
First of all, please realize that we did not start either of the world wars. And I'm not convinced that we participated in either of them in order to spread democracy. But that said, if this is the question you have been assigned, here's what I would say:
When Woodrow Wilson pushed for the US to enter WWI, he did it (you can argue) because he wanted to make the world safe for democracy. He thought that the autocratic governments of Germany and Austria-Hungary (both were monarchies) were bad for the world. He thought our way was superior and that we should help the other democracies to defeat the monarchies. This goes with the idea of Manifest Destiny since part of that idea is that we should spread our "superior" type of government and civilization to everyone.
In WWII, we only entered when attacked. But once we entered, our goal was to destroy Imperial Japan and Nazi Germany. We wanted to get rid of those systems altogether -- not just to push them back and let them continue to have those "bad" systems of government. That is why we did not allow either of them to make peace -- we forced them into unconditional surrender.
So in both cases, you can say that we're trying to spread democracy and freedom and that is part of what Manifest Destiny was about.
I think that you should start by defining Manifest Destiny. Then you should talk about each war in turn -- why we got into it and how that reason fits with Manifest Destiny. That will be a good, clear way to organize your essay.
You do need some clarification, but take a closer look at the very idea of manifest destiny and how it played out in our history before we get too carried away touting our defence of "democracy" in the 20th century.
Our manifest destiny always applied to the groups we wanted it to, it certainly didn't apply to native Americans or anyone else who got in the way of the expansion that those in power saw as the "destiny" of our country.
In the 20th century, we continued to expand on this idea outside of our borders, taking control of the Phillipines with some creative maneuvering and then taking the stage as a world power. Often it was less about protecting democracy and much more along the lines of taking what we thought was rightfully ours, including colonies of our own.
I think that you are going to have to engage in some strong explanation and detail if you are going to proceed with this topic. It is a fascinating one and can reveal much, but be prepared to undertake some significant analysis and assertions that have substantiated. O'Sullivan's statement about how "providence" has granted America the ability to stretch its borders from "sea to shining sea" helped to play a major role in the expansion of the nation. It became something seen as fulfilment of a spiritual duty to engage in American expansion. This helped to form the nation that we now know today. It also helped to spin off into foreign expansion and into dollar diplomacy as well as justifying American imperialism. It will be along these lines that you might want to explain American entry into World War I and II. The challenge you are going to have is that both wars were justified by their leaders as wars to defend the democratic way of living and it has almost become accepted definition in standard views of American History to see it as such. It is not to say that it is right, but rather stressing that there needs to be detailed and precise analysis in making the argument that American faith in Manifest Destiny helped to justify expansion and eventual entrance into both World Wars. I would probably focus on how both wars helped to enhance American interests from the economic and geopolitical point of view, as opposed to being endeavors where the protection of democracy were the first and primary reason for entering into the conflicts.