Homework!

I'm sending you to the Library!
All links will be to World Cat, so you can find a copy closest to you.

The first few books I think you should see are:
Fashion from the Kyoto Costume Institute it has been published several times, including as a 2 book set. It covers the 18th through 20th centuries.

Revolution in Fashion: European Clothing 1715-1815, also from Kyoto features most of the same 18th and regency dresses, but it has the addition of three patterns from Janet Arnold

Patterns of Fashion 1: Englishwomen's Dresses and their Construction 1660-1860 by Janet Arnold this book includes patterns for women's dresses on a graphed scale, from original antique garments. Sketches of the dresses are given, but no photographs.

Seventeenth and Eighteenth Century Fashion in Detail from the V&A was previously published as Historical Fashion in Detail, You may also find it listed in your library as Fashion in Detail: Seventeenth and Eighteenth Century.

This turned into a series of books, Nineteenth Century Fashion in Detail has some Regency clothes, and Underwear in Detail has corsets from the time periods we are concerned with.

I think that is enough homework for now.
If your local library doesn't have these books, consider Inter Library Loan. or just spend some time in the costume history section.