http://www.avalon-tours.com/News/news97_6.html
Wasn't the Phylloxera present in the vines that went over there?
No, because the Phylloxera didn't exist in Europe before the vines came over in the late 1800's from California. The American vines are actually the resident host of this parasite - the carrier - and when the first vines arrived in Europe they brought the parasite with them. The French vines, Vinis Vinifera, are not resistant, and that's why the only solution was to graft the French vines onto the American rootstock which could survive the Phylloxera.
Were vines grafted in France before this?
No, vines were always propagated by cuttings before this - not only here but all over the world.
Why were the vines first brought over here from California?
I don't know; I suppose because someone wanted to try something new, to experiment, to see what would happen.
;-))