 The Commissioners' Court meets the first and third Tuesday at the Commissioners' Courtroom located in the Dallas County Administration Building at 411 Elm St., corner of Elm and Houston streets.The building was the headquarters of the Texas School Book Depository Company until 1970.Assassin Lee Harvey Oswald shot President John F. Kennedy from a window located on the sixth floor which today houses the Sixth Floor Museum dedicated to the late president's memory.