Alice's Adventures in Wonderland was written in the 1860s, during the Victorian era. Men wore three piece suits, women wore long dresses with corsets and crinolines, and young girls wore over the knee dresses with pinafores to protect them. For the Wikipedia entry on 1860s fashion follow the related link below.
The dress is by Alice + Olivia, but it came out last year so it may no longer be in stores.
Alice's dress is a Diane von furstenburg dress. i own it and found at the saks 5th avenue outlet. i got the dress for $60 when its original price was $470. but I'm sure they are gone by now though larger sizes might still be available and are able to be altered. :)
Macy's
The dress is from Jenny Packham. You can find the link in related links.
The clothing worn in the film was created by a wardrobe department specifically for that film. Many of the costumes are CGI and really do not exist. The main human characters wore real clothes. You could get some shots and have something similar made but you would have to be aware of copyright .
Ellie wore her sister's dress.
In the costume department.
Jennifer lopez; she wore The green dress
Bjork wore a swan dress to the Oscar's in 2001.
Where can you find the black and cream skirt that Katherine Hegl wore in the movie 27 dress?
The dress was a one off designed for the role. It has not be created for commercial purposes.