I am not real knowledgeable about what happened in Michigan in the early union days and I guess there was right and wrong on both sides. Possibly the state and maybe the federal government sent in enforcers to break up the strike or allowed the company owners to hire people to violate rights of strikers. Not sure.
Unions help people negotiate from strength of unity. Imagine there are no labor laws or a Dept of Labor. You and some fellow workers know your employer just got a big contract; the bunch of you contract with a union to take your immediate demand or no work tomorrow. That is strength through unity of a union and there is nothing wrong with that.