Semi-Common Given Names in the South, circa 1800's

In our research, we all know that some given names that had nicknames commonly used for them.Example:females named Sarah were commonly called 'Sally', and Elizabeth's were commonly called 'Betsy' or 'Eliza', or a Jane was often called 'Jincy', and on and on.And we all know that some given names were fairly common during an era in certain parts of the country, due to being named in honor of a regional or local hero or admired person.

But there are two given names I keep running into in my research that I'm curious about, and wondering if anyone might have some insight into the reason or origin of them.I run into these two names not only in my own ancestors of the 1880's, but when checking census pages for my ancestors, I see the names in other families as well.

The first one is the female name 'Hulda'.I see it in use calling females that name when it isn't even part of their actual given name.For instance, my great-grandmother's full name was Nancy Louise Evans, yet all her life she was called 'Hulda' by her family.She was asked about this once, and she said she had no idea why, she just knew her family had always called her that.And I've seen similar versions of that same story hundreds of times in genealogy forums and reports/queries/discussions, etc. where a woman's given name is whatever, but she's called 'Hulda' as a nickname.Anyone know the origin or reason for this?My ancestors were predominately from the American south, so this is where I find it, no idea if that nickname was common anywhere else.

The other name I'm curious about is the male given name of Pinkney... again found in the South in the 1800's fairly commonly.I find the given name in both pre-Civil War and post-Civil War South, in at least 5 states.And again, this 'Pinkney' name is an actual given name, not a nickname.Does anyone know the origin or reason for popularity of this male given name during the 1800's in the South?