Hello,
I am a Junior in college majoring in History w/ a concentration in Secondary Education so I can teach high school social studies. I am writing a paper in my U.S. Historical Geography course concerning the U.S. Civil War and the effects of historical geography on different battles (i.e. terrain, disease pathology, human-environment interaction). My college has access to JSTOR, but it is a love-hate relationship. Some paper topics are easy to research using JSTOR, while others, such as any topic I could have chosen from this super niche class of Historical Geography, seem virtually impossible to write effectively. I have tried every search tip as I can to find relevant sources, including the advanced search where you include multiple keywords that are all allegedly included in the papers. However, when I search things like "American Civil War," + "Historical Geography," + "Nature." I get a horde of irrelevant articles. I have found about fifty articles so far, and have only included seven in my annotated bibliography, with only three being more than just vague mentions of the impact of geographical challenges during the Civil War. Other articles that randomly pop up include things like "National Tourism during the Spanish Civil War," "The Saltwater Revolution: the Oceanography Civil War," and "The War on Drugs in the Modern United States." This irrelevance of sources makes me want to rip my hair out. So, please help me out with this:
When you have an article or book you find useful, it's possible using a couple of methods to find later articles that cite the one you have. You may find these useful as well.
Marquette U. has a guide about how to do this with both JSTOR and Google Scholar.
Academia.com is also a possible resource. I get an email every time someone references my dissertation, which is frustratingly rare.
I find JSTOR's search function to be quasi-useless unless I already know what I'm looking for.
If your own school doesn't have a large library, go to the catalog of one that does that's also more easily searchable (use the library catalog at a large R1 like Texas, for example; most of them allow you to search their catalog without being a student there--you need to be affiliated in order to access the articles), find an article (or author of an article) that seems relevant, and then go to JSTOR to access it. Once you've found something good, JSTOR has a "related articles" function (again, kinda hit or miss, but not as bad as the search function).
Google Scholar is also another database that's also much easier to search (since most of us have learned how to manipulate Google searches to get what we want). Google Scholar is also where you can plug in the title of an article or book that you've already found, as u/LegalAction suggests, to see which other papers and authors cite it.
And, if you don't have access, go through ILL, or you can also email the author directly. Most of the time, we're happy to supply copies of our articles to people who ask!
I very, very rarely ever use the actual database to search. Because the way different journals upload and provide access to their digital content is such a mess, it's not worth it to spend time on searching on a single database.
My first stop is Google Scholar. Because it pulls from so many sources, this is a good way to explore and experiment with search terms. Maybe "historical geography" isn't what you're looking for. Google Scholar recommends related searches. I searched "civil war use of landscape features," got recommended the related search "environmental history of the civil war," and that lead me to this book and this book, which I believe is exactly what you are looking for. Google Scholar also makes it very easy to see other sources that have cited an article, which is useful when the list isn't too long.
Sometimes I will compliment this by searching on my university library's site. I find this to be better when I am looking for a specific type of publication, e.g. a book or a book review. These are rarely built as nicely as Google Scholar. Often, you'll find a source on Google and then search it again on your library so that you can find how to access it.
Once I've got a few solid sources, most of my research is done in their bibliographies. I have several PDFs files that are almost illegible from me aggressively marking up every citation that I want to follow up on.