The Old Terrorism: A Dataset, 1860—1969

Since the 9/11 terrorist attacks, research on terrorism has grown exponentially. Data limitations, however, have made temporal generalization difficult. Most terrorism datasets extend back only to the 1970s, which inhibits the ability to quantitatively examine earlier waves of terrorism. To address this limitation, this article presents a dataset of over 250 terrorist organizations formed between 1860 and 1969. These data, which have global coverage, include country-year information on group formation, allowing scholars to examine the relationship between various country-year factors and the emergence of terrorist organizations. To illustrate their usefulness, these data are used to examine the relationship between democracy and terrorist group formation. Following several recent studies, the empirical analysis reveals a curvilinear or inverted u-shaped relationship between terrorism and democracy.