I recently read somewhere - sorry no citation and bad memory - that in the South, it was the custom to use one's middle name rather than their first name. I certainly found this to be true in the case of my Southern Grandpa and his family.
I found Thomas Walter Canty listed as "Walter Cantey" in 1900 in Augusta, Georgia. He was living with his father "Jas A Cantey," his brother "Willie Cantey," and his two sisters, "Jennie Cantey" and "Pearl Cantey." With the exception of the father and oldest brother, three of the children were listed by their middle names. By searching online for Barnwell, South Carolina history, I found some information about the Canty (or Cantey as it seemed to be used interchangeably) family from that area. I was blessed to actually find the first and last names of James A. Cantey and his children. Using both the first and middle names, I was able to locate this 1900 Census.
So Grandpa was 13 years old and living with his father and three siblings, his mother apparently having passed away. Fast forward to 1909 and Grandpa had gone to his sister Jennie's sister-in-law in Ohio and had signed up for the Army. I believe that his father also passed away sometime during this period because I find each child in a different location. Sadie "Pearl" Canty was living with her sister who was now Jenny Beard. Willie was married and on his own.
In addition to the middle name being used, my experience has also found that nicknames were recorded in census reports as well. So we have first names, middle names, nicknames, misspelllings on last names and marrying, remarrying and name changes. Whew! But it becomes so exciting when a new fact is learned. Just yesterday, I learned that my Grand Aunt Jennie was actually Virginia P. Canty. But that's another story.