Reams of nonsense have been written about the "Persons Case" over the years, and the above link [in the OP] is no exception.
"Women were not always considered 'persons' in the legal sense of the term," it begins. The fact is that there was no "legal sense of the term". "Person" (or "persons") was not a legal term of art. It had the same meaning in law as it had in ordinary parlance.
The Supreme Court never considered that the word "persons" in general did not include women. In this case, it considered the use of the word "persons" in the specific and narrow context of s. 24 of the British North America Act, which provided for the appointment of "qualified persons" to the Senate of Canada. (Note that the link above never mentions this salient fact.)
The question was whether the drafters of the BNA Act of 1867 intended "qualified persons" in s. 24 to refer to women as well as men, since at that time women had no legal political rights and were not considered "qualified persons" to hold public office. The Supreme Court decided that it was not the intention of the original BNA Act to include women among those eligible to be Senators, which was almost certainly true, but it betrayed a reluctance on the part of the Supreme Court to recognize that the constitution should be interpreted as a living document, not a fossilized one.
The Privy Council overturned the Supreme Court decision, not on the basis of a more enlightened view of constitutional interpretation (or of the status of women) but on the narrow, technical (and probably incorrect in substance) ground that the original drafters of the BNA Act did not use clear language to indicate that they had men only in mind when they drafted s. 24, and therefore they must be taken to have intended to include women in the term "qualified persons" - because the ordinary meaning of "persons" included women.
In my view, the Privy Council simply resorted to a legal fiction in order to arrive at a just result. I believe the BNA Act never in fact intended to provide for women to have any political rights at all.
In any event, we always hear the nonsense about how the Privy Council decided that "women are persons" - as if there had been any doubt of this fact among the population of Canada. Even in the Supreme Court decision, Chief Justice Anglin had expressly said,"'Persons' is not a 'word importing the masculine gender.'" All the Privy Council decided was that the word persons included women in s. 24 of the BNA Act, in the absence of any additional wording to show that women were intended to be excluded. That is definitely not the same thing as deciding that "women were persons", a fact which was assumed from the outset, and beyond dispute. In fact, long before this case, women had already won the right to vote and the right to run for public office.
"And so it came to pass that in 1929, women acquired the right to exercise official functions, to attend university, and to practice a liberal trade." So says the link in the OP. In fact, the decision had nothing to do with any of those matters specifically.
Thus the celebration of Persons Day is not the celebration of a great change in the way the law viewed women. Rather it is the celebration of a legal decision that allowed women to be appointed to sit in the undemocratic chamber known as the Senate. When viewed in the correct context, the case was actually a minor victory in the long struggle for women's rights, which began long before then and continues to this day.
[ 18 October 2008: Message edited by: M. Spector ]