Michael LeMay is Professor Emeritus at California State University, and an author of more than 2 dozen academic titles. His latest, "U.S. Immigration Policy, Ethnicity, and Religion in American History" is a very readable overview of our story of immigration over the past 200 years. Michael sees it as a door, as immigration is about persons entering the country. He organizes US Immigration policy into 6 doors, beginning in 1820 with the Open Door Era, followed by the Door Ajar Era, the Pet Door Era, the Dutch Door Era, the Revolving Door Era of 1985-2001, the now we are living in the Storm Door Era. It's not just fascinating, it's illuminating, and gives us a better understanding of the politics, the the challenges. http://mikelemayimmigration.blogspot.com/p/blog-page.html