where did this type of democracy that you mentioned originate?
It traces its origins to the Age of Enlightenment.
Liberal democracy
Liberal democracy traces its origins—and its name—to the European 18th-century, also known as the Age of Enlightenment. 
when was the declaration of i dependence signed 1776 what is this document? The pronouncement adopted by the Second Continental Congress meeting in Philadelphia. what does this document tell about slaves? The apparent contradiction between the claim that "all men are created equal" and the existence of American slavery attracted comment when the Declaration was first published. and about women? There is a part in it which demanded social and political equality for women. were any other countries inspired by this declaration? France and Vietnam. how? The inspiration and content of the French Declaration of the Rights of Man and of the Citizen (1789) emerged largely from the ideals of the American Revolution. what is this declaration that you just mentioned? A human civil rights document from the French Revolution. can you provide me the historical background of this declaration? The content of the document emerged largely from the ideals of the Enlightenment. The principal drafts were prepared by Lafayette, working at times with his close friend Thomas Jefferson. what is its legacy? It has also influenced and inspired rights-based liberal democracy throughout the world.
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Liberal democracy [SEP] Origins
Liberal democracy traces its origins—and its name—to the European 18th-century, also known as the Age of Enlightenment. At the time, the vast majority of European states were monarchies, with political power held either by the monarch or the aristocracy. The possibility of democracy had not been a seriously considered political theory since classical antiquity and the widely held belief was that democracies would be inherently unstable and chaotic in their policies due to the changing whims of the people. It was further believed that democracy was contrary to human nature, as human beings were seen to be inherently evil, violent and in need of a strong leader to restrain their destructive impulses.