Because the "Powers that Were" were fugging stupid and should have taken a course in economics.
^Although the EU has caused many major economic problems and will continue to do so including the impending collapse of the ECB it is all the stupid democratically elected national governments faults. As we know it today it exists to create a single 'state of Europe', with authoritarian governance.
1957. The European Union was formed on 1st November 1957
The European Union's de facto capital is Brussels.
The European Community
The Euro.
1991
The European Union wasn't formed instantly. It is a result of the combo of various institutions that initially promoted a European Community. This turned to a Union, after agreeing on the basis of a treaty.
November 1 1993
What was then called the European Economic Community was founded in 1957. It later became known as the European Community and then on the 1st of November 1993 it became known as the European Union.
European Union
The Treaty on the European Union or the Maastricht Treaty
The European Union.
The European Union