Minutemen was a group of people who were afraid of communism. Imagine if you had a toy that someone else wanted, but they said if you didn't give it to them, they would take it anyway. That's what the Minutemen were afraid the communist countries like Russia and China might do to America.
They wanted to make sure America was safe from communism, so they started keeping an eye out for any signs that it was trying to sneak in. They would watch for suspicious people or groups that they thought might be helping communism. They even built special hiding places where they could store weapons in case they needed to defend themselves.
The Minutemen also wanted to make sure everyone knew how bad communism was. They would go to meetings and talk to people about why they should be against it. Sometimes they even had rallies or protests to show everyone how passionate they were about their cause.
Overall, the Minutemen were just trying to protect America from communism and make sure everyone knew how dangerous it could be.