Missouri Bollingers in the Civil War

Have recently finished reading Bartels' Civil War Stories of Missouri and found a few references to Bollingers within those pages. While the book doesn't provide any references to it source materials, I'll list the individuals and what information can be gleaned from the pages here for those interested in extending their research on this sur-name.

George Bollinger - slave of Del (or Dal) Bollinger and his wife (Aunt Polly or Mary Bollinger) Interview with George was conducted around 1935
Kate Bollinger - daughter of Del (or Dal) Bollinger and his wife (Aunt Polly or Mary Bollinger)
Del (or Dal) Bollinger killed during Civil War by men trying to steal from him.

Olive Bollinger (daugher of a slave owner from around Sabula, Missouri) married John Higdon (from Colorado) Higdon fought for the South at the battle of Fredericktown and was injured in the arm. Olive died in Rockport, AR leaving a small 2 year old child Little John.