The New York Public Library has created a project that is, to me, fascinating: a repository of thousands of American restaurant menus from the past two centuries. Their easy to use web site allows for easy browsing of menus by year, and, incredibly, each menu item is also catalogued, so you can trace the rise and fall of, say, chicken a la king, as it travels from non-existent to omnipresent and back again to obscurity.
Here's some sample menus to you can see what delights await you on the library's site. Well done, New York Public Library!