photo from: Beach Erosion Board archives via World of Decay
A recent re-analysis of the hurricane seasons during the years 1941 - 1945 was recently concluded. This new analysis has resulted in four new tropical storms being added to the list of storms to hit the US. Re-evaluations of known storms has also resulted in several storms having their category ratings changed.
The Atlantic Hurricane Database Re-analysis Project is a project undertaken by the National Oceanic & Atmospheric Administration (NOAA) to provide a more accurate record of tropical weather dating back to 1851. The reason this project exists is because prior to the 1950s the record of tropical weather was quite spotty. Unless a storm hit a populated land mass or was witnessed by a ship at sea it went unnoticed. Radar was introduced in limited use after WW2, but it wasn't until the mid-1950s that technology was sufficient to reliably catch every tropical storm that formed.
Notable hurricanes in these years include the 1944 Great Atlantic Hurricane, which affected North Carolina, the mid-Atlantic states, and New England, killing 390 people. This hurricane was downgraded from a Saffir-Simpson Hurricane Wind Scale Category 3 at landfall in New York to a Category 2. Also in 1944 a late season Caribbean hurricane that struck Cuba causing 315 fatalities has been upgraded from a Category 3 to a Category 4 major hurricane at landfall. Additionally, in September 1945 a major hurricane struck Homestead, Florida - bearing many similarities in size, track, and impact to 1992's Hurricane Andrew - and was upgraded from a Category 3 to a Category 4 at landfall.
You can read the entirety of the re-evaluation report which so far covers from 1851 - 1945 here.