How has US healthcare changed in the last 50 years

I actually know a good amount of general information about the topic because we exposed to it very briefly in my Health Science 180 class. I know that insurance has grown much more complex over the last 50 years. I know health insurance was started during World War 2 by private companies because wages were froze so employers couldn't offer better wages but could give additional benefits such as health insurance to their employees. I know that back then it was a much simpler system ,but I am not really sure exactly how it worked. I am familiar with current insurance practices and how current insurance works at least enough to explain the basics. Some other things that I know are that healthcare costs dramatically increased during the late 1970s and 1980s and there are some possible reasons for this. One is that there were new advances in diagnostic tests and new drugs that were created during this period.