If that Martian looked at battlefields, they would find that people had only muskets at the time of the Civil War and that they had repeating rifles at the time of the Spanish-American War, and then they had machine guns by the time of World War I.
Si ese marciano observara  los campos de batalla, descubriría que las personas  solo contaban con mosquetes durante la Guerra Civil y que tenían fusiles de repetición para la Guerra Hispanoestadounidense, y tenían ametralladoras para la Primera Guerra Mundial.