I am quite impressed with the amount of work you put into your reply, especially since you aren't related! Thank you.
I have done quite a bit of research on the Ratleys since I originally posted this message. I believe that it is my FamilySearch Pedigree file that you used. the child originally transcribed as "Reese" on the 1900 census is actually Bessie. I found Mary Lula living with her daughter Bessie Ratley Hunter in 1920.
I found a newspaper article from the Americus (GA) Times through which I learned that Louis E Ratley died in Dothan, AL in December 1897. It didn't mention cause of death and I don't believe that there are any death certificates in Alabama during that time frame.
I believe, based on death certificates, that the two unmarked graves in Ozark, Alabama are Mary Lula and her son James. However, no one in Dale County, including the Historical Society, seems to know where the Union cemetery records are located and therefore I cannot find any other documentation to prove this theory.
Now my brick wall in this family is Mary Lula's parents. I have her death notice from Columbus, but it only mentions her children; no parents or siblings of Mary Lula's are mentioned. I have death certificates for three of her four children, and none of them mention her maiden name. I have ruled out a couple of families in my search, but have not had success yet. I'm thinking of ordering the Social Security application for one of Mary Lula's children in the hope that it might mention her maiden name.
I really appreciate the time and research that you have done. Thank you again!