Watch the Ruthenian Threat!
By Chris Bertram lists the 46 races, circa 1914:
African (black), Armenian, Bohemian, Bosnian, Bulgarian, Chinese, Croatian, Cuban, Dalmatian, Dutch, East Indian, English, Finnish, Flemish, French, German, Greek, Hebrew, Herzogovinian, Irish, Italian (North), Italian (South), Japanese, Korean, Lithuanian, Magyar, Mexican, Montenegrin, Moravian, Pacific Islander, Polish, Portuguese, Roumanian, Russian, Ruthenian (Russniak), Scandinavian (Norwegians, Danes, and Swedes), Scotch, Servian, Slovak, Slovenian, Spanish, Spanish-American, Syrian, Turkish, Welsh, West Indian.