Certain words, used in a certain way, take a comma after them all the time. City/state listings follow this rule; so do dates. (There is an official term for this kind of list, but I’ve forgotten what it is.)
Examples:
I lived in Hartford, Connecticut, before I went to school.
Compare with: I lived in Connecticut before I went to school.
**I wrote the check on December 12, 1998, and mailed it on January 1, 2000. ** (A comma always goes after the “1998” when this construction is used.)
Compare with: I wrote the check on 12 December 1998 and mailed it on 1 January 2000. (Commas are unnecessary)
So, in the examples given, the second sentence is incorrectly punctuated.
Either is correct, but I’d for flow I’d probably use the second. But your question brings up a related issue: the gradual disappearance of the serial semicolon. I can’t think of any examples right now, but I frequently come across situations in which the lack of a semicolon leads to real confusion. Usually when there’s a series of titles, one of which includes a comma.
(To add my vote: In order to reconcile some of the discrepancies in the many different “reliable” sources, I had to write a house style manual for a company where I used to work as a copyeditor. After considering all the arguments, I too went with using rather than omitting the final serial comma.)
If in doubt, say it out loud. If you pause at all during some of it, put a comma in the place you paused. I often get crazy with the commas. But the rule I always use is, if you are listing two things, (apples and oranges), you do not need a comma. If you are listing three or more (apples, monkeys, and oranges), use a comma. Please. Otherwise, it annoys me.
Other rules that override the “saying it out loud” rule are: City, State; Person’s Name (before and after), and Year (before and after). Usually.
As for semicolons, I love those, too. If you went to Madison, Wisconson; New York, New York; and Sacramento, California, please punctuate it as I have done.
Others have said that either is correct. I suppose I can’t argue with that, especially since there are experts among them. But I have a degree in English, so I felt I should respond, since I am so anal about commas.
My understanding is that commas to set off an appositive (e.g., “John Smith, the acclaimed philosopher, indicated that…”) are superfluous when the appositive is so closely related to the word(s) it modifies that it does not serve to distinguish the precedent from something else (e.g., “Smith, the philosopher,” not “Smith, the pastry chef”). This is called, I believe, a restrictive appositive. For example, since one generally has just one mother, the commas would be unnecessary.
I will freely admit that I have not seen this rule followed consistently either way, but why should I let that stand in the way of a perfectly good, anal-retentive grammar question?