In which city did "Wicked" make its musical debut?

It's easy to look at the almost $2 billion in ticket sales for "Wicked" and assume it was always destined to be a hit, but it started as a risky musical adaption of a not-so-famous novel that was a reframing of an extremely famous story. Mixed reviews of musical numbers and songs that demanded serious vocals meant there was no room for error. Where did this future Broadway cash cow first test whether audiences were ready to root for the green girl?