Just for the record, the earliest to make landfall was Alma and it happened on June 8, 1966.
The Florida Keys count as landfall. Don’t know where the article gets first landfall in 1966. Hurricane Donna went right through Central FL in 1960. Galveston, TX hurricane was devastating in 1900 greatest natural disaster in US history, so stated.
Donna: https://journals.ametsoc.org/view/journals/mwre/89/3/1520-0493_1961_089_0099_thso_2_0_co_2.xml
Galveston: https://en.wikipedia.org/wiki/1900_Galveston_hurricane