The Vegetarian Resource Group has a number of interesting articles in the history section of their website www.vrg.org
For example, we have a link to the American Vegetarian Health Journal published in the mid 18oos in Philadelphia, PA. There’s another piece titled: History of Seventh-day Adventist Work with Soyfoods, Vegetarianism, Meat Alternatives, Wheat Gluten, Dietary Fiber and Peanut Butter (1863-2013). You will also find articles on individuals such as Amos Bronson Alcott, Dr. John Harvey Kellogg, Benjamin Franklin, Sylvester Graham, and many others.
The history section can be found here: http://www.vrg.org/history/