Juneteenth at the Sam Houston Center - Exhibit Program with Edward T. Cotham Jr., Author of Juneteenth: The Story Behind the Celebration. Commemorate the 160th anniversary of Juneteenth with the Humanities Texas exhibit Juneteenth from June 3 - July 1. Join us for the exhibit program on Saturday, June 14 at 1:00 p.m. when Edward T. Cotham Jr. will discuss his book, Juneteenth: The Story Behind the Celebration. The Center will also offer a special viewing of historic documents.