These are from the Lesbian Herstory Archives! They have a collection of over 2000 historical lesbian buttons, and were able to get them all scanned and documented over the period of 10 years. There's a ton here, and they've carefully catalogued as much as they can about where they came from too.
Loving this "How dare you presume I'm heterosexual!" button that's apparently from the Oscar Wilde Memorial Bookstore.