<Li> USS New Ironsides </Li> <Li> Grimball's Causeway </Li> <P> The Battle of Natural Bridge was a battle during the American Civil War, fought in what is now Woodville, Florida, near Tallahassee, on March 6, 1865 . A small band of Confederate troops and volunteers, mostly composed of teenagers from the nearby Florida Military and Collegiate Institute that would later become Florida State University, and the elderly, protected by breastworks, prevented a detachment of United States Colored Troops from crossing the Natural Bridge on the St. Marks River . The Natural Bridge is a one - quarter mile long stretch along which the St. Marks River runs underground, after dropping into a sinkhole . This action prevented the Union Army from capturing the Florida capital and made Tallahassee the only Confederate capital east of the Mississippi River not to be captured by Union forces during the war . The battle has been described as the last Confederate victory in the American Civil War, and it was the second largest American Civil War battle in Florida . </P> <P> The Union's Brig. Gen. John Newton had undertaken a joint force expedition to engage and destroy Confederate troops that had attacked at Cedar Keys, Florida and Fort Myers and were allegedly encamped somewhere around St. Marks . The Union Navy had trouble getting its ships up the St. Marks River . The Union Army force, however, had advanced and, after finding one bridge destroyed, started before dawn on March 6 to attempt to cross the river at Natural Bridge . The Union troops initially pushed Rebel forces back, but not away from the bridge . </P>

Why was the battle of natural bridge significant during the civil war
find me the text answering this question