Why didn't the US want communism?

Because we wanted freedom not something blurring on the lines of slavery.

A2: Although communism is effective, it is unpopular among the people.

So it ussually requires some sort of pre-established basis for it. And a large force of army or police to enforce fear factor. Since the country was united with all the people fighting together in an army, a communism was unthinkable. It would have torn the country apart, if it had gone anywhere. It probably would have resulted in the supporters just being kicked out.

Once a democracy is established, people will rarely want to switch to a communism. If they do, if was because a demcoracy was an utter failure and fell to ruins.

As for blurring on the lines of slvary, I find this to be wrong. America still managed to have slaves? In fact, Russia, a communist nation, beat Amerida to ridding of slaves by about 150 years.

I find the lack of perspective on different types of government arrogant. All government types have their advantages.