This page has photos of actual 19th century garments, which I find useful for inspiration.
Most of these photos were found on eBay and antique garment dealers, like: Maire McLeod Elegant Vintage; Karen Augusta Antique Lace & Fashion; Antique & Vintage Dress Gallery; FiddyBee; Time Travelers; 1860-1890; Rupert & Toby's Collectables; HeartNSoul1; Old Threads Antique Textiles.
Another site with lots of excellent images is Démodé: Extant women's clothing 1750-1919.
Click on thumbnails to view larger images.
Brown cotton polonaise, c. 1880
Embroidered organza gown, c. 1880
images courtesy of Maire McLeod Elegant Vintage
Brown silk & velvet bustled skirt, c. 1880
Cage bustle, c. 1880
Gold brocade & ivory silk satin reception gown, c. 1880
Tan satin R&G corset with lace trim, c. 1880
White muslin (wedding?) gown, c. 1880
Three-piece hip pad, 1880s
Black silk beaded pelerine, 1880s
Black silk brocade jacket, 1880s
Black velvet and ecru lace reception gown, 1880s
Black wool bat-wing coat with braiding, 1880s
Girls blue dotted print dress, 1880s
Blue silk bustle gown, 1880s
Worth beaded black velvet & lace capelet, 1880s. Gorgeous!
Brown velveteen & copper silk bustle dress, 1880s