Worst for that area, but not the “worst” for the US, or even Florida in general, I believe.
Labor Day Hurricane of 1935—The most powerful hurricane to make landfall in the United States. A very small storm, this Category Five Hurricane tore through the Florida Keys with 180 mph winds, and a low pressure of 26.35 inches of Hg.
http://www.hurricaneville.com/1935_hurricane.html
For Reference:
NOAA Technical Memorandum NWS NHC-6
THE DEADLIEST, COSTLIEST, AND MOST INTENSE UNITED
STATES TROPICAL CYCLONES FROM 1851 TO 2010 (AND
OTHER FREQUENTLY REQUESTED HURRICANE FACTS)
Eric S. Blake
Christopher W. Landsea
NHC Miami
Ethan J. Gibney
I.M. Systems Group
NCDC Asheville
National Weather Service
National Hurricane Center
Miami, Florida
August 2011
http://www.nhc.noaa.gov/pdf/nws-nhc-6.pdf
2004-05 were as bad as I care for with Charley, Frances, Jeanne and Wilma tearing up my neighborhood.