OK, I don't normally like to just repost content from other places, but this is super-cool and relevant for designers (or, frankly, anyone who likes old pictures and documents). NYPL Labs, a digital-focussed arm of the New York Public Library system, has made freely available to the public a huge number of delicious, high-resolution images of out-of-copyright materials. The release includes some really cool stuff.
From the library's website:
The public domain release spans the breadth and depth of NYPL's holdings, from the Library's rich New York City collection, historic maps, botanical illustrations, unique manuscripts, photographs, ancient religious texts, and more.
I obviously haven't been through the entire collection, but even a cursory glance has yielded some gems, like these old menus.
At the time when I wrote this, the website seemed to be having some (understandable) bandwidth issues which caused some difficulty in viewing and downloading images, but if you're patient enough, it's well worth it to check this out. This nifty visualization tool will allow you to navigate and sort through the collection.
Here's the full story about the release on the NYPL blog:
http://www.nypl.org/blog/2016/01/05/share-public-domain-collections