The correct answer to this open question is the following.
The first democratic government was established in ancient Greece, specifically in Athens, Greece. It was the ideas of Solon and later Cleisthenes, the Athenian leader, that allowed democracy to flourish in ancient Greece. This democratic system or the "rule of people," allowed Greek male citizens to elect their rulers.
Magna Carta shaped democracy in the United States in that it was an English document written by rebel barons to put an end to the absolutist power of English King Jhon. Magna Carta was signed by the King on June 15, 1215. It limited the power of the English crown and made the King accountable to the law.
Magna Carta influenced the founding father and the framers of the Constitution on the idea of limited powers for the federal government, and the creation of the division of powers.