I've been trolling through the Met site for about the past 2 weeks (it's so huge). If you type in "Brooklyn Museum" as a keyword, you'll get the 3900+ garments they recently added into their database from that museum. I like that they keep adding things into their database.
(I've found that I have to limit my trolling to the time it takes me to drink a large mug of decaf or I spend way too much time there).
I've been doing a bit of Regency dress research for a friend who has a perfect figure for that period, doesn't like heavy corsetry & wants to build a Regency wardrobe. I'm finding resources for her, as she is not very web/computer-savvy. It's a fun computer learning exercise for her to use the sites i point her to for the clothing she wants to look at.