Nassau County, Florida: History
Nassau County was created in 1824 from Duval County. It was named for the Duchy of Nassau in Germany.
The Battle of Alligator Bridge took place in Nassau County around Callahan on June 30, 1778, and was the only major engagement in an unsuccessful campaign to conquer British East Florida during the American Revolutionary War.
In 1817, the short-lived Republic of the Floridas was established on Amelia Island. It was one of several attempts to wrest Florida from Spanish control into the growing United States.
Some of the men from the county had formed a militia unit called the Davis Guards leading up to the Civil War. This unit would be organized as Company K of the 2nd Florida Infantry Regiment in the Confederate army.