Producers avoided making movies about controversial subjects.
The House of Un-American Activities Committee (HUAC) was a committee of the House of Representatives that was meant to investigate subversive activities. In particular, they were meant to investigate private citizens and companies that had Communist ties. The control that the HUAC exercised meant that many topics were not addressed in movies, as they were considered too controversial and, therefore, risky.
It changed the nature of free speech and free association. People could easily avoid being questioned if they would name someone who was a member of the communist party at any time. That turned friend and coworker against friend and coworker.
Eventually that immunity wore off because people were naming the same people. That's when things got really dicey. Now you were forced to either plead guilty or name someone else.
You can find out a lot more by searching out Dalton Trumbo. You can also search out Kirk Douglas' use of Tumbro's name for Spartacus. It was a very courageous move.
the viking voyages took place during the middle ages, which was about this time. 500 to 1350. the viking voyages took place during the middle ages, which was about this time.