As with many other branch-mint Morgans, the 1879-O was once considered exceptionally scarce until bag quantities began appearing in the mid 20th century. Today, the 1879-O Morgan dollar is very common through at least MS65 though becomes more challenging above that, with piece grading MS66 or better considerably rare. PL and DMPLs are much scarcer still and extremely rare in grades of MS65 or higher.