This is an intricate "Patriotic" post card commemorating "Decoration Day" and the Grand Army of the Republic, which was an organization of veterans of the union Army during the American civil war (or the war between the states, if you're from the south).
This card has embossing on top of embossing. The five pointed star has the words "Grand Army of the Republic, 1861-1865". On back it includes "Decoration Day Series No. 2" as part of the publisher information.
Decoration Day began in the south after the end of the civil war, and referred to the custom of visiting and decorating the graves of soldiers who had died during that conflict. This developed into a national observance, typically on May 30th, and evolved into the present Memorial Day holiday.
I do not know the exact date of this card, but I'm pretty sure it would be in the 1908 to 1912 era.