Complex sentence: He has done all of this because Andy will shoot the President of the United States in 2013 at a ceremony marking the 150th anniversary of the battle in honor of the flag of Confederate states of America.
Split into simpler sentences: He has done all of this because Andy will shoot the President of the United States in 2013 at a ceremony marking the 150th anniversary of the battle. He does this in honor of the flag of Confederate states of America.