This list is certainly not complete—that’s impossible!—but it should provide you with starting points and ideas to launch your research.
In-person sources
Books, magazines, fashion plates, extant examples
To view:
Major museums (see on-line sources for suggestions)
Local museum exhibits
Local museum collections (contact and request to view)
Historical societies (ditto)
Conferences
University libraries
Local libraries using inter-library loan (ask your librarian!)
To purchase:
Ebay
Etsy
Facebook groups (see on-line sources for suggestions)
Private dealers
Major auction houses (see on-line sources for suggestions)
Local auction houses
Antique stores, antique malls
Used bookstores
Estate sales, flea markets (you never know what you’ll find!)
On-line sources
Period books and magazines
Free:
Google Books
Hathi Trust
Archive.org
University of Düsseldorf
Subscription:
Accessible Archives
Newspapers.com
Compilations of links to period books and magazines
Jessamyn’s Civil War-era fashion publication link list
Beth Chamberlain’s mid-century fashion publication Zotero database
Beth Chamberlain’s Mostly Pointless Drivel blog historical knitting publication link list
Fashion plates, drawings, paintings, and photographs
Los Angeles Public Library Casey Fashion Plates Collection
Library of Congress
Ebay
Daguerreobase
Bartos Collection
Europeana
Extant examples
Ebay
Etsy
Augusta Auctions
Charles A. Whitaker Auction Co.
Kerry Taylor Auctions
Museums with significant costume collections:
Fashion Institute of Design & Merchandising Museum
Kent State University
Los Angeles County Museum of Art
Met Museum
Museum of Fine Arts, Boston
Britain’s National Trust
Victoria & Albert Museum
…and too many more to count!
Facebook groups that share/sell unique extants and images:
Civilian Civil War Closet
Portraying Men of the mid-19th century
Victorian-70s Antique & Vintage Clothing Dating Help
Compiled links to extant examples
All the Pretty Dresses blog of images and info on extant clothing in private collections
Démodé’s link list of museums with digital collections of extant clothing
Anna Worden Bauersmith’s Pinterest pages, primarily focused on mid-century millinery
Jessamyn’s Pinterest pages, primarily focused on Civil War-era clothing and accessories