The North American Union (NAU) is a theoretical

The  North American Union ( NAU ) is a theoretical economic and political union of  Canada ,  Mexico , and the  United States . The concept is loosely based on the  European Union , occasionally including a common currency called the Amero or the North American  Dollar . A union of the North American continent, sometimes extending to Central and South America, has been the subject of academic concepts for over a century, as well as becoming a common trope in science fiction . One reason for the difficulty in realizing the concept is that individual developments in each region have failed to prioritize a larger union.

More recently some form of union has been discussed or proposed in academic, business, and political circles, for decades. ^{[1] [2] [3] [4]} However, government officials from all three nations say there are no plans to create a North American Union and that no agreement to do so has been signed. ^{[5] [6] [7]} The formation of a North American Union has been the subject of various  conspiracy theories . ^{[8] [9] [10] [11]}

http://en.wikipedia.org/wiki/North_American_Union