Millions of things are different. The most obvious being where the literature was written and who wrote it. But there are different values, ideas, experiences, styles, forms, and so forth.
There will be large differences between the two (and within the two) depending on the time period as well For good British Lit see: Shakespeare, Samuel Taylor Coleridge, Lord Byron, John Donne, Christopher Marlowe, etc For good American Lit see: Emily Dickinson, W.E. B Du Bois, T. S Eliot, Walt Whitman, William Carlos Williams, Henry David Thoreau, Nathaniel Hawthorne, Herman Melville, etc.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.