Whats wrong with the Articles of Confederation?

It really didn't work well. The country was too fragmented to make the Articles work. We needed the Constitution. The problem is that the writers, particularly James Madison, took a strict constructionist view, i.e. the government could ONLY do what the Constitution specified. However, the loose constructionists like Alexander Hamilton started us on the downhill slide to intrusive expanding government. John Marshall didn't help much either.