After the 9/11 and san bernardino terrorist attacks, many americans treated muslims quite differently, even though they stated that they were not prejudiced. these negative feelings were a part of their:

After the 9/11 and san bernardino terrorist attacks, many americans starte treating muslims quite differently, these negative feelings were a part of their Islamophobia developed after these events, it is a fear or rejection towards Muslims or people of Arab origin, this term had already been created by a British Non-gubernamental organisation but it was after september 11th attack that spread around the word. 

February 1848 is when it was added. if that's what you were asking