There is a good biography of Armour by Harper Leech and John Charles Carroll, Armour and His Times (1938). See also Rudolf A. Clemen, The American Livestock and Meat Industry (1923; abr. 1966) and By-Products in the Packing Industry (1927); and Louis F. Swift and Arthur Van Vlissingen, Jr., The Yankee of the Yards: The Biography of Gustavus Franklin Swift (1927).
"Philip Danforth Armour." YourDictionary, n.d. Web. 10 April 2019. <https://biography.yourdictionary.com/philip-danforth-armour>.