▁was ▁sparse ▁and ▁they ▁held ▁compar atively ▁few ▁slaves . ▁African ▁slaves ▁arrived ▁in ▁Florida ▁in ▁ 1 5 3 9 ▁with ▁Hern ando ▁de ▁S oto , ▁and ▁in ▁the ▁ 1 5 6 5 ▁found ing ▁of ▁St . ▁August ine , ▁Florida . ▁ ▁The ▁Spanish ▁promised ▁freedom ▁to ▁refuge e ▁slaves ▁from ▁the ▁English ▁colon ies ▁of ▁South ▁Carolina ▁and ▁Georgia ▁in ▁order ▁to ▁dest abil ize ▁English ▁settlement . ▁▁ ▁If ▁the ▁slaves ▁converted ▁to ▁Catholic ism ▁and ▁agreed ▁to ▁serve ▁in ▁a ▁milit ia ▁for ▁Spain , ▁they ▁could ▁become ▁Spanish ▁citizens . ▁By ▁ 1 7 3 0 ▁the ▁black ▁settlement ▁known ▁as ▁Fort ▁M ose ▁developed ▁near ▁St . ▁August ine ▁and ▁was ▁later ▁fort ified . ▁There ▁were ▁two ▁known ▁Fort ▁M ose ▁sites ▁in ▁the ▁eigh teenth ▁century , ▁and ▁the ▁men ▁helped ▁defend ▁St . ▁August ine ▁against ▁the ▁British . ▁It ▁is ▁" the ▁only ▁known ▁free ▁black ▁town ▁in ▁the ▁present - day ▁southern ▁United ▁States ▁that ▁a ▁European ▁colonial ▁government - sp ons ored . ▁The ▁Fort ▁M ose ▁Site , ▁today ▁a ▁National ▁Historic ▁Land mark , ▁is ▁the ▁location ▁of ▁the ▁second ▁Fort ▁M ose ." ▁During ▁the ▁nin ete enth ▁century , ▁this ▁site ▁became ▁mar sh ▁and ▁wet lands . ▁ ▁In ▁ 1 7 6 3 , ▁Great ▁Britain ▁took ▁over ▁Florida ▁in ▁an ▁exchange ▁with ▁Spain ▁after ▁defe ating ▁France ▁in ▁the ▁Seven ▁Years ' ▁War . ▁Spain ▁ev acu ated ▁its ▁citizens