Based upon our research this appears to be a Civil War era US Union Army issued bullseye canteen model 1858, however we are not experts in military memorabilia from this era. The canteen is covered in a heavy cloth fabric with nice dark patina. It has the original cork and chain and a rope strap which was probably a soldier’s field repair to replace the original fabric strap. Other than some torn stitching on the cover (see photos) it’s in nice condition with soiling, dents and abrasions consistent with its age and battle use. The canteen is approximately 8 1/2” in diameter and 4” wide.