1288 - 1968 15c Prominent Americans: Oliver Wendell Holmes。91 - 1867 15c Abraham Lincoln, Black, E Grill, Perf. 12 - Mystic。Value of US Stamps Scott Catalog #98 - 15c 1868 Lincoln Grill。Most Expensive: 65 most expensive (valuable) American stamps - YouTube。15 stamps + AlbumTheme: Nelson Mandela, Peace