America didn't have a hereditary nobility, and plenty were inclined to build one. The Senate was supposed to be like the House of Lords. Initially the states were free to nominate senators as they saw fit; they are now directly elected (can't remember exactly when that changed). There were people who wanted to make George Washington the new King. The fact that the founders held so many different ideas about how to run the new country was one of the reasons they came up with such a weak Federal government as existed from the American Revolution up until basically the (American) Civil War. There were only a few things they could all agree that the government should do, such as run the military and pay off the war debt. Though nominally a continuous government since 1787(+/-), we aren't living under the same system as back then.