Looking for some more heirloom cover crops to honor European and black settlers.

Good evening folks! I'm looking to add some cover crops to my Three or Five sister gardens before the year's out. Which cover crops are safe to plant in my Three Sister gardens this fall? I know buckwheats and rye came from European settlers, but are there more out there which help enrich the soil and life into our gardens year in and year out? could rye, oats and other stuff work also? I've planted marigolds for butterflies and stuff in my Three Sister garden and went ok. Please reach me if you need me. Good night!