american civil war appomattox campaign appomattox court house army of northern virginia army of the james army of the potomac artillery battle of appomattox station battle of five forks battle of palmito ranch cavalry confederate states army edmund kirby smith edward porter alexander first battle of bull run fitzhugh lee george armstrong custer george crook james longstreet john gibbon north carolina parole philip sheridan siege of petersburg skirmisher stand watie union army united states virginia wilmer mclean