The flu season is in full swing and reported cases are spreading quickly throughout the U.S. Take a look at history's four main flu outbreaks.
6 / 12
CDC/HHS
1968 – 1969
In early 1968, a new flu virus was detected in Hong Kong. The first cases in the United States were detected as early as September 1968 and the virus spread quickly. Deaths from this virus peaked in December 1968 and January 1969.