This is an American Civil War bullet also known as a Minié ball as it was named after its co-developer, Claude-Étienne Minié. This specific Minié Ball was removed from a wounded soldier during the Battle of Chickamauga which took place from September 19-20, 1863. With 34,000 casualties, the Battle of Chickamauga is generally known as the second bloodiest engagement of the war; after the Battle of Gettysburg which had 51,000 casualties This type of bullet was known to cause an enormous wound on impact. Made from lead, it was so heavy that an abdominal or head wound was almost always fatal and a hit to an extremity usually shattered any bone encountered.https://digitalcommons.molloy.edu/nur_hagan/1052/thumbnail.jp