It's not just that we are a democracy. That's nothing special. Democracy has been around since the ancient Greeks. Many other countries today have democracies. But not like ours. Ours is unique because at the outset of the country, the founding fathers decided that our government would be limited in its authority over the people. There were specific and enumerated responsibilities for government in the Constitution, all subject to the God-given and inalienable rights of the individual. Unlike in other countries, the government does not bestow rights upon the people. Rather, the people bestow power to the government, power which they are free to revoke at any time.
In insisting that our government be limited, the founding fathers were reacting to the persecution they faced in Europe. Almost all the land was owned by the King and a few rich aristocrats, while the peasants, the people who actually worked the land and produced goods, had to pay an exorbitant amount in tribute. To make matters worse, they had no right to challenge their leaders, since in most cases, Kingship was considered a divine, inherited right. It would be preposterous for a person of humble birth to even dream of challenging the status quo, much less one day ruling the land.
We set out to change all that. We were wary of an imbalance of power - whether political or economic - concentrated in the hands of a few. Still, at the birth of our country, the temptation to revert back to monarchy, even a constitutional monarchy was strong. George Washington was in fact offered the opportunity to become King of America: an honor he wisely rejected. Instead, a system of limited, divided government was put in place. The three branches had, in theory, co-equal power, so that they could check excesses in each other.