The red sunlight symbolizes the mass amounts of blood spilled during the war. It is not clear what war Poe is referring too, however at the time of the writing of this poem both the war of 1812 and the wars of Spanish American independence were under way.
Lake Dock, Thousand Islands, Canada. The Light Purple & Blues Of The Hills, Water & Sky In The Background Create A Cool Tone To The Image. The Leaves Complement It Well & Add To The Peace & Tranquility.