After having read through this scenario, determine what, if any, legal issues and concepts would apply to this situation?

Bill has worked at a manufacturing plant as a Maintenance Technician for the past 30 years, he started when he was 28. When he began, Bill worked the 3rd shift, which was the least desirable of all the shifts (for him personally). It took him nearly 5 years to move to a 1st shift job and he has worked that shift ever since and has no desire to work a different shift. Because of his tenure and performance, Bill tends to work autonomously with little direction from his supervisor.

Bill has had the same supervisor for the past 10 years, however his supervisor recently retired. The company replaced him with John, an outside hire who just graduated from college. John has a very different management style than his former supervisor and in Bills opinion, micro-manages him.

Since John started, Bill noticed that some of his more technical/advanced job duties were being reassigned to other, less-experienced maintenance technicians. Bill is concerned about this because the work that he is receiving instead was what he describes as grunt work.

The situation escalated one day when John informed Bill that he was moving him to the 3rd shift to be more compatible with the job duties that he is currently performing. In response, Bill handed his security badge to John and informed him that he was resigning, effective immediately.