Krable Krablez

Specifically, I would like to know this. When he was President, George Washington lived (mostly) in the State House on Market Street in Philadelphia. It was the largest house in Philadelphia in those days. However, it looks like an ordinary house. It has a front door and a porch. If you were passing by and felt you needed a little rest, you could sit on the porch. That's what it looks like in the pictures (it's not there anymore).

So here's my question. If you had a question that could only be answered by the President; or an issue that you felt could only be resolved by the President; or an idea you absolutely had to share with the President - i.e. if you wanted to, well, DROP BY - how would you go about it?

What would happen if you just knocked on the door? Would a steward or butler open it for you and ask you what you wanted? Would he let you in? Would the President (if he were at home) be informed then? Or would you be asked to come back some other day? (Would there be guards nearby, or inside the house?)

That's the first part of the question.

Now for the second part. If you COULD visit the President JUST LIKE THAT, would there be huge crowds of people outside the house, each person waiting his/her turn to speak to him?

Finally, the third part. I vaguely remember a tradition (in these United States) that absolutely any U.S. citizen who wanted to do so could visit his President on a certain day of the week (Tuesday or Thursday, I'm not sure) at a certain hour. Who started this tradition, and why? When did it end, and why?

Any and all answers will be greatly appreciated.