MLA International Bibliography is the best place to start your search for literary criticism. It is organized by subject, and it contains scholarly articles, books, and book chapters. Not everything is full text, but SSU Library can get you anything through Interlibrary Loan.
Using Advanced Search, look for the exact title or author of your work in "Primary Subject Author" or "Primary Subject Work"
To find the Uniform Title, do a basic search of the title or author of your work and look for the General Subject Area, and then look for the Primary Subject Author or Primary Subject Work.
Subject Terms are database supplied keywords about an article. These contain things like: treatment of women, post-colonialism, relationship to historical events, etc. Literary theory terms will show up here. Not all articles have these subject terms.
JSTOR is a full text database. It does not have a subject search. When you search JSTOR, you are searching the entirety of every article in the database. You will get a lot of false positives. Searching for Harriet Beecher Stowe will return hits on Harriet Tubman, Henry Ward Beecher, and Stowe, Vermont.
Here are some tips to make searching JSTOR more productive.
Start with JSTOR's Advanced Search.
From here, you can limit your search to your search words showing up in the title or abstract of an article. Not all articles have abstracts, though.
You can also scroll down to narrow your results by type (article, review, book), publication date, and language, and finally by discipline and journal title. Some useful disciplines for Harriet Beecher Stowe would be
Project MUSE is a full text database without a subjec search, like JSTOR.
Start by searching for your title or author in a basic search
From the Results screen, you can choose search limiters from the boxes on the left. Start by selecting a Research Area, like "Literature > American Literature." Scroll down to see other limiters, like Year, Language, and Journal Name.