This page is a work in progress.
I have discovered there are many anime and manga series that are set in the past and the characters wear Western clothing. Here is just a small list of them:
Shuvarie (Le Chevalier d’Eon) – Paris 1742
Hakushaku to Yōsei (Earl and Fairy)
Kuroshitsuji (Black Butler) – Victorian but after Albert’s death
Eikoku Koi Monogatari Emma (Emma: A Victorian Romance)
The Cain Saga / Godchild
Croisée in a Foreign Labyrinth (late 1800s)
Gosick – 1924
Baccano! – 1920s
Chrono Crusade – 1920s
Knowing where you can get patterns or help in making costumes can tremendously help you in your cosplay plans. If you have a local costuming guild in your area, they can be of great assistance.
Here is a small list of sources of historical patterns: