It was in January, 1827, that Jefferson County was formed out of Leon, with its western boundary nearly the same as at present and the eastern boundary remaining at the Suwannee until December, 1827, when Madison County was established. Thus Jefferson County became a separate territorial division and governmental organization, after being at times a part of the provinces of East Florida and West Florida, and of the counties of Escambia, Jackson, Gadsden, and Leon. It extends from the Georgia line to the Gulf, a distance of about forty miles, and at the base line is about twenty miles wide. Its area is 593 square miles.
"Jefferson County, Florida, 1827-1910. Part I,"
Florida Historical Quarterly: Vol. 7:
2, Article 7.
Available at: https://stars.library.ucf.edu/fhq/vol7/iss2/7