It turns out that a library nearby has a pretty decent reference section with cookbooks dating back to 1800 or earlier. I may plan a trip.
In the meantime, I’m looking through google books and finding an 1888 transcription of 15th century cookery books, including the first gingerbread recipe I’ve found (which doesn’t have ginger in it).
Gyngerbrede. — Take a quart of hony & sethe it, & skeme it clene; take Safroun, pouder Pepir, & throw theron; take gratyd Brede, & make it so chargeant that it wol be y-lechyd; then take pouder Canelle, & straw ther-on y-now; then make yt square, lyke as thou wolt leche yt; take when thou lechyst hyt, an caste Box leves a-bouyn, y-stykyd ther-on, on clowys. An if thou wold have it Red, colour it with Saunderys y-now.
(translation: boil a quart of honey, skim the top, add Saffron and ground black pepper. Take grated bread and make the mix so thick you can cut it. Then add cinnamon. Make it in a square in preparation for cutting it. Cover it with box leaves with cloves stuck into them (to decorate it). If you want red gingerbread, color it with Sandalwood.
Directly related, according to google, the Baptist Lady’s Cook Book (1895) has a number of ginger cookie receipts as well. They are very different from what we are used to with directions like “flour to make as thick as poundcake”
The 1796 gingerbread I made was fairly popular at work. Huzzah!