What is the author's style in Albion's Seed: Four British Folkways in America by David Hackett Fischer?

Fischer's entire work is lengthy enough to be deemed a 'tome'. While there are only four folkways described: each is covered in sufficient detail to have caused the entire work to take over 700 pages. The author provides prefaces, and other introductions as well as supplemental materials at the end of the body of the text.