They were established by agreements between political or social entities who control those areas (kings etc.)
The meeting of the Estates-General in 1789 was convened by King Louis XVI (B). It was an attempt to solve the financial crisis France was in.
In 1789 France was in crisis. Agriculture wasn’t doing well and the price of the bread soared. Poor people paid the largest part of taxes and practically sustained the aristocracy. The country was broke because of all the wars it had participated in the last years.
Due to the financial crisis, Louis XVI convened the Estates-General, a great assembly composed by the clergy (first estate), the aristocracy (second estate) and the ordinary people (third estate). Throughout the country, people met and registered in <em>cahiers</em> or register books their problems with the government that were to be taken to the main assembly.
The ordinary people, noticing they would lose any polling since they had one vote against two (first and second estates'), left the Estates-General and assembled in a tennis court nearby declaring themselves the National Assembly.
The refusal of the ordinary people to take part in a political event that would maintain that society was still divided in estates is an illustration of the transformation French Revolution was causing. From then on society was no longer organized and perceived as it were in medieval times. That was one of the beginnings of Modernity.
George Washington was the first president of THE UNITED STATES OF AMERICA.
He also warned against the danger of political parties.
