Honestly, I almost hate to answer this question because this statue makes me really uncomfortable. It's a reminder of a shameful period in our country's past, that ugly and lamentable era during which whites saw African Americans as objects of pity and hatred, scorn and contempt.
I'm talking, of course, about last week, when conservative guru William Bennett proclaimed on national TV that "You could abort every black baby in this country, and your crime rate would go down."
So if you don't mind, I'll indulge in some white liberal guilt for a few hundred words before answering your question.
Unveiled in 1900 to honor Foster, who was born in Lawrenceville in 1826, the statue is only slightly less offensive than Bill Bennett's unique approach to crime reduction. According to a contemporaneous account reprinted in Discovering Pittsburgh's Sculpture, here's how one of the project's overseers wanted the thing to look: "the poet seated, notebook in hand, catching the inspiration for his melodies from the fingers of an old darkey reclining at his feet strumming negro airs upon an old banjo."
Yikes. Perhaps it's no surprise that the statue was vandalized almost from the moment sculptor Giuseppe Moretti cast it. Discovering recounts that Foster's pencil was stolen a half-dozen times, the banjo at least twice. Finally, in 1944 the statue was moved from Highland Park to its current location so it would "be safer and more visible." Now we're all stuck looking at it. Thanks a lot, vandals.
Of course, some would argue that this statue, like Foster's lyrics, needs to be viewed in the context of its time. It's been pointed out, for example, that in the sculpture, Foster is jotting down the music to his song "Uncle Ned" ... which some contend has an abolitionist sentiment. "When Old Ned die Massa take it mighty bad," the song goes. "De tears run down like de rain." According to the argument, this emotional reaction proves that Foster, and even Ned's master, recognizes Ned's humanity.
I find this argument totally unconvincing. Slave owners may have missed their slaves -- especially when they had to do the work themselves -- but that doesn't mean they had the moral intelligence to recognize slaves as human. Slave-owners probably felt bad when their favorite horse died too. Mawkish sentiment, in other words, is no substitute for justice.
But bizarre sentiments attach themselves to the statue even today. To answer your question, rubbing the big toe on the slave's right foot has been considered a sort of good-luck ritual for years. That portion of the statue, in fact, has been rubbed for luck so many times that the metal on it is burnished -- free of the green patina that covers the rest of the bronze statue.
Why? Who the hell knows? Rubbing statues for good luck is an old tradition among some. And Roadsideamerica.com, a popular site for patrons of unlikely tourist attractions, asserts "shoes are usually the most-rubbed part of a statue, on the theory that good luck, like gold, sinks." The site even lists the Foster statue by name: "The 'lucky toe' of the slave who sits at the base of the Stephen Foster statue (Pittsburgh, Pennsylvania) is an example of a rare, unclad foot. It is extremely powerful."
Well, you can certainly see how much use it's been to the slave depicted on the statue, or to the much-maligned statue itself. And at the risk of sounding too PC (I know, I know: too late!) I have to say that this quirk utterly fails to charm me. To me, it just smacks of the same original sin that created the statue in the first place: Once again, the shame of slavery is being deployed for entertainment purposes, serving the whims of the master class.
If you ask me, instead of rubbing the statue, we'd be better off rubbing it out. Let's just shove the Foster statue into a hidden corner somewhere, where it could gather dust and serve as a reminder of just how idiotic we can be sometimes.
Come to think of it, we ought to do the same thing with Bill Bennett.