U.S. National Government and why it's needed

Why do we need U.S. National Government? Yes, some may think it's an outdated system but all things need structure to achieve great success. America needed structure 240 years ago and that first attempt at structure was known as the Articles of Confederation which was effective for nine years. In those years the Articles of Confederation defined the powers of the federal government and the 13 states. This was a big achievement for the U.S. but there were still countless inconsistencies which created a weak federal government; no regulation on trade or levied taxes, tariff wars, debt, etc. So the states drafted the U.S. Constitution which allowed even more structure and has continued to be a "living document" throughout the last 200 years. I think the failure of the Articles of confederation is a perfect example of why we desperately need a strong National Government. Without it we would could have no coin money, war without regulation, no control over conducting foreign relations, and improper foreign interstate trade. It's also a privilege that the Constitution can be amended as times change and generations evolve all because we have a strong National Government in place.