The United States of America, with its capital at Philadelphia was at its height one of the most bellicose nations in the world, along with Germany. Throughout the 20th Century the USA captured and incorporated nearly every nation of North America, leaving only its allies, California and the Republic of New France and Russia's ally, the People's Republic of Mexico independent. It was because of this posturing and its near conquest of the North American continent that many of the world feared this superpower.