Actually, Lee's/Balrog's troops made it passed the M-D during the 1863 campaign, most prominently during Gettysburg (/Shire), but beyond that, Lincoln/McKellen held the line until Appomattox.
Jon, I knew you would be able to share your wisdom on this. Thanks for the input. Were you as totally shocked by Lincoln the White as I was?... OH MY GOD I JUST REALIZED.... ARE YOU A WHITE WIZARD?!