The trick to searching any database effectively (whether library catalog or article database) is knowing how different searches work.
Keyword Searches look for your search terms in all the data fields (title, author, publisher, notes, subjects, etc.). This generates a broad list of results but will also have irrelevant material because your term showed up somewhere in the record. The library catalog assumes an "AND" when you do a keyword search and will only give you the records that contain ALL your search terms unless you use "OR."
Result: more hits but extraneous material included
Subject Heading Searches use a "controlled vocabulary," which is fancy talk for a limited number of words used to describe everything. These are specific subjects that librarians have assigned to each book or article.
Result: fewer hits but almost all are relevant
Keyword Search is to Subject Search as Google is to Database Searching. You get fewer but better hits searching our Subscription Databases.
Some suggested subject headings to search for:
Tourism -- Dictionaries
Tourism -- Social aspects
Tourism -- [insert location]
Food -- Social aspects
North American -- Discovery and exploration
Travel in literature
Travel -- Medieval
Travelers in literature
Travelers' writings, American
Travelers' writings, American -- History and criticism
Travelers' writings, European
Travelers' writings -- History and criticism
West (U.S.) -- Discovery and exploration