Like the EU, should the North/South American countries form a union?

Given the historical context between North, Central and South America the prospects do not really appear conducive to such a union.

The EU has rules for inclusion, such as allowing free markets. An AU could do the same thing, incentivizing poorer countries to modernize. An AU would also be a framework for accelerating the development of the poor American countries, like the EU. The EU helped Ireland and Spain develop by improving infrastructure and other things in those countries. The U.S. and Canada could do the same for all the other countries in the AU.

All countries of American continent should form a union to compete in this global world, especially with European Union.

There are alot of advantages that came from the formation of EU. Transaction costs were eliminated, which especially in the business realm proved to be useful since countries such as England have firms who spend over a billion dollars per year buying/selling foreign currencies. In fact, anything to do with currencies- price transparency (being able to actual compare goods easily), establishing a single currency in an essentially single market, low inflation rates, etc etc all were positive results from this union.
However, despite that I feel like this type of union would simply not work with America. Part of the reason that the EU was established was so they could be on the competitive level of the Japanese Yen and American Dollar.. also to establish a strong union within a continent that was split up into many many (often feuding) nations.
North America/South America are not as comparable to Europe as one would assume. There is such a huge discrepancy between nations of the Americas versus between nations in Europe. If a union were to be established, America would naturally be the country to dominate and even rule it. The feasibility for each nation in the EU to have a similar weight was much more likely to happen than North/South America could hope for. Moreover, America does not have much of an issue with currency rates and such with nations within North/South America as it does with Europe/Asia. Hence the core reasons alone that the EU was established is not as applicable to the Americas.

Moreover, you also have the list of disadvantages that could easily occur from a union that would be especially pertinent to the US. US would have to undergo many structural changes in terms of their economy and business; that is something that entrepreneurs I doubt will accept (even if in the long run they gain from these changes.) Again, because of the over domineering tendencies of the US, this would be a definite loss of power for nations especially in South America. With any union involves fees and heavy financial burdens, and I don't see all nations being as cooperative as the nations of the EU (who were not all that cooperative themselves.)

Hence, although it may have for the most part worked well with the EU, I don't see the Americas being built to form a similar type of union.