Smithsonian specialty
I believe the answer is:
americana
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">smithsonian specialty</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for americana that I've seen before include "Things from the USA" , "Wild West material?" , "continental collection" , "Uncle Sam's things" , "Foreign collection" .)