Twain's family was in Hamburg only one known time, April 25-30, 1878, though Sam and Joe Twichell were there for two days Aug. 20 to 21, 1892; and Sam went again (alone?) on Aug. 25 and 26 to meet the Prince of Wales.

See Bædeker Northern Germany (1886) page 162

Bædeker Northern Germany (1873)