Both Search It and Worldcat will search across libraries globally; but this expansion of Search It *just* happened, so it might be best to try your searches in both to capture everything available. Two ways to go about this:

Search Keywords: [War/Tribe/Nation name] AND (atlas OR map) (Example: Modoc AND (atlas OR map))

• If you cannot find your specific war or population, just try: Indian* war* AND (atlas OR map) - this will give you a long list. Your battle or population may be contained within the work, so read the full record. ALSO look at the Format and Description, as it might list that maps might be contained within the work.
• Why the asterisk after Indian war? Searching either Indian or Indians, or war or wars gives different results! The asterisk searches both variations at once.
• Also note: Searching Indian might bring back materials about India. You could also add "American" or U.S., for example.

Search Subject Headings: You can also try a subject heading, which is like a hashtag that brings together all sources that have been "tagged" with that subject. These can be complicated and inconsistent, so I suggest finding a related book and then looking at the subject headings, and then clicking them to see what is out there. A few examples:

Once you are in the results page of a subject heading, you can click on "Advanced Search" on the right of the search box, and then enter a keyword into the next search box as well. For example, if I search Indians of North America -- Wars, and then open up the advanced screen and type Modoc as a keyword, I'll get everythig under that heading that mentions Modoc somewhere. Just another way to refine your search.

You could also search the name of your tribe or nation in the search box, switching it to "Contains" and "Subject," like the example in the screenshot below. This searches the word in ALL subject headings so you don't have to build something complicated.