Question: When did the european union start and for what main reason?

Disambiguated questions and answers:
context: No context provided
question: For what main reason did the european union start originally?
short_answers: Supranational union

supranational foundation

supranational foundation that would "make war unthinkable and materially impossible"and reinforce democracy amongst its members

multinational political union

context: Apart from the ideas of federation, confederation, or customs union such as Winston Churchill's 1946 call for a "United States of Europe", the original development of the European Union was based on a supranational foundation that would "make war unthinkable and materially impossible" and reinforce democracy amongst its members as laid out by Robert Schuman and other leaders in the Schuman Declaration (1950) and the Europe Declaration (1951). This principle was at the heart of the European Coal and Steel Community (ECSC) (1951), the Treaty of Paris (1951), and later the Treaty of Rome (1958) which established the European Economic Community (EEC) and the European Atomic Energy Community (EAEC). The ECSC expired in 2002, while the EAEC maintains a distinct legal identity despite sharing members and institutions.
question: According to Winston Churchill, the european union started originally to answer what call?
short_answers: call for a "United States of Europe"

"United States of Europe"
wikipage: History of the European Union

context: With a wave of new enlargements on the way, the Maastricht Treaty was signed on 7 February 1992 which established the European Union when it came into force the following year.
question: When did the Maastricht Treaty start the european union?
short_answers: 1992

7 February 1992
wikipage: History of the European Union

context: On 30 March 1994, accession negotiations concluded with Austria, Sweden and Finland. Meanwhile, Norway, Iceland and Liechtenstein joined the European Economic Area (which entered into force on 1 January 1994), an organisation that allowed European Free Trade Association states to enter the Single European Market. The following year, the Schengen Agreement came into force between seven members, expanding to include nearly all others by the end of 1996. The 1990s also saw the further development of the euro. 1 January 1994 saw the second stage of the Economic and Monetary Union of the European Union begin with the establishment of the European Monetary Institute and at the start of 1999 the euro as a currency was launched and the European Central Bank was established. On 1 January 2002, notes and coins were put into circulation, replacing the old currencies entirely.
question: When did the european union start indicated by creation of a common currency?
short_answers: 1 January

1999
wikipage: History of the European Union

Long answers:
knowledge: content: The Maastricht Treaty (1992) created the European Union with its pillars system, including foreign and home affairs alongside the European Community. This in turn led to the creation of the single European currency, the euro (launched 1999).
wikipage: History of the European Union
long_answer: Apart from the ideas of federation, confederation, or customs union such as Winston Churchill's 1946 call for a "United States of Europe", the original development of the European Union was based on a supranational foundation that would "make war unthinkable and materially impossible" and reinforce democracy amongst its members as laid out by Robert Schuman and other leaders in the Schuman Declaration and the Europe Declaration. The Maastricht Treaty,1992, created the European Union with its pillars system, including foreign and home affairs alongside the European Community. This in turn led to the creation of the single European currency, the euro, launched 1999.