Souvenir Program. From the Fort Ethan Alen Living History Day August 1, 2009. Celebrating the 100th Anniversary of the Tenth Cavalry's arrival at the Fort in 1909, A 12 page booklet with 2 page center fold map of the Fort. A Brief History of the Fort. Program of events. The 10th Cavalry Soldiers in Vermont. Speaker Biographies: Colonel Franklin J Henderson, LTC Christian J Heidorf. Sponsors, Ads, etc. $2.50 plus 2.50 P&H. Please add sales tax if Vermont address.