After doing more detailed research, I’ve narrowed down my research topic: How does education, and the lack thereof, affect life expectancy in America? I'm going to see how the life expectancy of people with little education (less than a high school diploma) compares to that of people with a high school diploma and how that compares to people with a college education.
On GIL-Find, I didn’t really find too many books that seemed relevant to my research. The most helpful sounding one I found is The New Worklife Expectancy Tables: By Gender, Level of Educational Attainment, and Level of Work Disability by Anthony Gamboa. I think looking at the educational attainment section would be a good source of info for my research. The book is at Georgia State University, though, so I’d have to request it first. But besides this book, the other books I found didn't seem to focus much on the educational aspect of life expectancy. I tried key words such as “life expectancy,” “education,” and “effects of education on life expectancy,” but I didn’t get much. Most of the books focused on the health related aspects of life expectancy.
For primary sources of information I could probably use records from places such as the United States Census Bureau.