Historic Marker number four is located at 429 Caroline Street between Duval and Whitehead Streets. The house you are looking at was originally built in 1839 as a two story house. In 1870 a third floor, featuring a mansard roof and gable dormers, was added. The mansion has a wonderful mix of Bahamian, New England and French architectural elements. Notice the elaborate ornamentation of porch posts and hand-wrought iron balconies. The mansion is best known for one of its inhabitants, Dr. Joseph Yates Porter, Florida's first Public Health Officer. Dr. Porter was instrumental in discovering that yellow fever was carried and spread by mosquitoes. Prior to this discovery, many ill-founded remedies were used to rid communities of the deadly disease. One of the most common of these was the use of quarantines. Ships would be detained in port and whole communities would be restricted from traveling to neighboring towns. Another remedy was to burn all a patient's belongings. Dr. Porter and his colleagues put an end to these practices and to the scourge of Florida that had lasted from before the Civil War well into the early 1900's. Dr. Porter lived in the mansion for 80 years and died in the same room in which he was born.