Otto Christian Archibald von Bismarck died on 1975-12-24.
Christian Archibald Herter - physician - died on 1910-12-05.
Christian Otto Mohr died in 1918.
Otto Christian Hammer died on 1892-03-10.
Otto von Bismarck died on July 30, 1898 at the age of 83.
Given that he was 83, I think it's fairly safe to say "natural causes."
Archibald Pinnell died in 1904.
Archibald Rutledge died in 1973.
Archibald Mitchelson died in 1945.
Archibald Randall died in 1846.
Archibald Rowlands died in 1953.
Archibald Gracie died in 1829.
Archibald Gardner died in 1902.