The US constitution got written after the US got independent and not before.

They wanted to create a government which was democratic, at least to a certain extent. They had a revolution. And they got one. It's true that some of the exact details weren't written down until after the Revolution, but they didn't have a revolution and then get a dictatorship, or something unsustainable, or find that all private property was abolished two years later--they got something which was clearly within the parameters they were trying to achieve.

They could do that by letting other countries send people to tell them how to run their country. They didn't do that because they themselves knew how to create a democratic state with free markets.

That's taking a very narrow interpretation of "planned to introduce". If you had asked them "when you overthrow the Communists, do you plan to have a free market system", they would have said yes. I count that as "planning to introduce a free market system, and getting what they planned for".

This is trivially true if you mean that no revolution produced the desired result up to the end of time. But then, the same is true of anything any human being does.

If my project is to lock my apartment with my key, then I can be quite certain that the result with look roughly like I plan beforehand.

The point of that sentence was to rule out saying "But if you look at the government over 200 years later, they clearly wouldn't have anticipated high tax rates and gay marriage, so they didn't get the system they wanted". If the system produced by the revolution is at least as stable as a non-revolutionary system, even if it has enough instability to show up after 200 years, it should count.