Within a few short decades in the early 20th century, the United States went from being a middling power to being the most powerful nation on Earth. Was this a major shock to the former Great Powers, or had there been a growing sense of "American inevitability"?

by derstherower

The United States was not viewed as a "Great Power" on the level of nations like the United Kingdom or France until around 1900 or so. Less than 50 years later the US had become a superpower with only the Soviet Union able to challenge its authority. Did this massive change in the geopolitical landscape just come out of nowhere, or had there been a growing idea of America eventually taking over, and it was solely a matter of when, not if?

xanderf

How early? With the 1803 sale of Louisiana to the fledgling United States, it is widely reported...

Napoleon is said to have exclaimed upon completing the bargain, "This accession of territory strengthens forever the power of the United States. I have just given England a maritime rival that will, sooner or later, humble her pride"

(technically not a primary source, but the link is from an 1881 publication - "America: an encyclopaedia of its history and biography")