The Okefenokee is the biggest swamp in North America. Part of it was helped by Franklin Roosevelt when he took a bunch of it and made it into a wildlife refuge. Before that, people could take trees away. Now the swamp has loads of animals.

how would i write this to make it more formal

The Okefenokee Swamp boasts the distinction of being the largest swamp in North America. Notably, a significant portion of this vast wetland was designated as a wildlife refuge through the initiatives of Franklin Roosevelt. Prior to its protection, the swamp faced the removal of trees by individuals. Consequently, the refuge is now teeming with diverse wildlife populations.

To denote a more formal tone, the provided description about the Okefenokee swamp and its transformation by Franklin Roosevelt into a wildlife refuge can be written as follows:

The Okefenokee swamp is recognized as the largest swamp in North America. This unique ecological habitat has undergone significant conservation efforts, including the intervention of Franklin Roosevelt, who allocated a substantial portion of the swamp for the establishment of a wildlife refuge. Prior to this conservation initiative, the swamp was exploited for its timber resources. However, since the inception of the wildlife refuge, a multitude of diverse animal species have thrived within this protected area.

The Okefenokee Swamp is recognized as the largest swamp in North America. A significant portion of the swamp was conserved and transformed into a wildlife refuge with the assistance of Franklin Roosevelt. Prior to this conservation effort, the area was susceptible to tree harvesting. Consequently, the swamp now flourishes with abundant wildlife and diverse species.