 The fourth known tropical cyclone of the season , also known as the San Agapito Hurricane and the Great Middle Florida Hurricane of August 1851 , the storm was first observed on August 16 about 775 miles ( 1250 km ) east of Barbados . It tracked west @-@ northwestward , attaining hurricane status on August 17 as it approached the Lesser Antilles . Shortly thereafter , the hurricane passed between Antigua and Saint Kitts and later south of Saint Croix . On August 18 it brushed the southern coast of Puerto Rico , though it affected the entire island due to a large size of the storm . The next day it made landfall on the southern coast of the Dominican Republic . The cyclone rapidly weakened to tropical storm status over Hispaniola , though it regained hurricane status as it paralleled the southern coast of Cuba just offshore . Late on August 20 , the cyclone crossed western Cuba , briefly weakening to tropical storm status before again regaining hurricane status in the southeastern Gulf of Mexico . It quickly strengthened and reached peak winds of 115 mph ( 185 km / h ) early on August 23 about 215 miles ( 345 km ) south @-@ southeast of Pensacola , Florida . Turning northeastward , the hurricane moved ashore near Panama City , Florida at peak intensity , with an estimated barometric pressure of 960 mbar . It accelerated across the Southeastern United States , weakening to a tropical storm before exiting North Carolina into the Atlantic Ocean on August 25 . On August 27 , it was last observed over Newfoundland as a weak tropical storm . 
