The 1995 bombing of the murrah federal building in oklahoma brought awareness to americans of?

Terrorism--The event was the largest terrorist attack to that date in history. 

This event made US citizens aware of domestic terrorism and the idea of terrorist actions. It also brought light to the Waco siege once again as it was cited by McVeigh as a reason for his attack on the Murrah building. 

Existing to a lot of people