Why do people believe in all the six fake moon landings by America?

For one, I had hands on with the Apollo project. One of over 400000engineers.,

 Dear Anonymous, 

Why do people like you wish to be anonymous?, are you ashamed by the fact that you are unable to understand simple things?.

The evidence  of the moon landings (by film and spoken evidence, sometimes under oath)is abundant, please stop bothering the grown ups and go back to finger paints.

The joke section is thataway, dear.

For the same reasons you troll here!

Because they as dumb as bag of Spanners

make your case dinkledorf

There were actually 12 moon landings, but six of them were fake.

Difficult to determine which "fake moon landings by America" you are talking about.
Other people who have answered your question have wrongly concluded that you are talking about the six real landings (Apollo program).
I don't know that many fake Moon landings by America. The oldest one I know about is in the story From the Earth to the Moon (Jules Verne). In that story, the trip is organized by the Baltimore Gun Club who builds a gigantic canon to fire a manned capsule towards the Moon. That makes it an American project, I guess. However, I do not know of many people who still believe that this fake (or rather fictitious) landing was real.

There is a famous one (especially famous among hoaxers) in the movie 2001, a Space Odyssey where scientists go to the Moon aboard an American passenger spacecraft to analyze a strange artefact that had been underground for hundreds of thousands of years. Very few people believe that the landing in that movie represents true events, but who knows... many Americans do confuse what they see in movies with what happens in the real universe. 

we did not know until the discovery of fake News

Definitally a fake,probably filmed in the Nevada desert.