The work done by Matthew Fontaine Maury, Betty's father, during the American Civil War is chronicled in this book by his son, Richard L. Maury, the brother referred to as Dick in Betty's diary.
A Brief Sketch of the Work of Matthew Fontaine Maury During the War 1861-1865
by Richard L. Maury
Richmond, Whittet & Shepperson, 1915
Clicking on the link in the book's title will take you to Google Books where the book may be downloaded (free).