The father of psychology
William James was a functionalist during the late nineteenth century. He is considered the father of psychology and wrote the first psychology textbook. William taught at Harvard where he he taught and studied the psychology of religion and the will to believe. At this time there was huge controversy surrounding the practice of slavery which eventually led to a civil war. There was also an anti-imperialist movement which William was a part of.
I find William James as a very important guy. William James is considered the father of modern psychology which in itself demonstrates his importance. He dominated his school of thought, literally writing the book on it. William was strongly influenced by the anti-imperialist movement which occurred during his time period. His work, in my opinion, laid a good foundation for the rest of psychology to build off of.