The Bugle bears no copyright notice. As of October 2, 2018, a faithful and complete scan of the entire Bugle is available online from Virginia Tech. No page contains a copyright notice and it is therefore in the public domain.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.