We knew there was a outbreak in December in China, and possibly earlier. The first known death in the U.S. was on Feb. 29. Backtracking through the past does not change when we first became aware of the problem.
“The first known death in the U.S. was on Feb. 29.”
Actually that is the first acknowledged death date. There were people dying in the US from pneumonia, with a rapid and severe onset in November, most were written off as “the flu” did it.