The scene where everyone gathers in a large room to watch Kimmy throw the bouquet was filmed at Cuneo Museum and Gardens in Vernon Hills, Illinois. The movie crew removed the large carpet from the floor and stored it someplace - it took the museum staff several months to find it again.
Sarah Jessica Parker was originally offered the role of Julianne Potter, but she was not able to take the role because she was committed to HBO in order to play Carrie Bradshaw on Sex and the City (1998).
The trivia item below may give away important plot points.
In the original ending, after watching Michael and Kimberly leave the wedding reception, Julianne meets a man (played by John Corbett). This ending did not test well and audiences wanted to see more of George, so a new ending was filmed.