First year of the modified design with the motto added within the oval of stars on the reverse. As such, this date is always of interest to collectors. Unimpaired proofs and strictly uncirculated business strikes are both very rare. Akers rates 1866 proofs as more difficult than the proofs of 1862, '63, and '64, but not quite as scarce as those of 1865, '67, or '68. The number of survivors is probably in the range of 10-12 pieces.