Just one more point : "à + a name" for "someone's (anything)" is the old regular form that has lived on in Louisiana (and in places in the country in France). It has been replaced by "de + a name" in France today (only form considered grammatically correct).
But I have also seen a few examples of "de + a name" in the Dictionary of Louisiana French. So it probably depends on what part of Louisiana the speaker is from.
Apart from that, no particular connotation or difference (except in France, of course).

Christian