Like jake, this doesn't strictly belong on "The Pansies" list, but maybe I should change the list name/parameters... Anyway here's a definition:
"The Raines Law, passed by the New York State Legislature in 1896, banned the sale of liquor on Sundays, except at hotels, where guests could be served drinks during meals. Overnight, hundreds of bars put a few beds and chairs in their upstairs rooms, called themselves hotels, and kept a few plates of nominal food at hand to put in front of drinking customers. One of the great artifacts of the Gay 90s was the Raines Law sandwich, a desiccated slice of ham between two slices of stale bread that no customer ever touched."
(Article citation and link are in "The Pansies" list description.)