In the final episode of our American Terrorism series, we tell the story of the Columbine High School Massacre, in memorial of the 20th anniversary of April 20, 1999. We start with a brief history of school shootings in America, continue on to tell the stories of Eric Harris and Dylan Klebold, including the events of the massacre, then conclude with a non-exhaustive list of devastating and impactful shootings since 1999.