Henry Augustus Martindell (1857-1912) was born to Henry J. (1832-1907) and Matilda J. (1835-1923) Martindell. He married Georgiana Freas (1867-1948), with whom he had one child, and worked as a private secretary in his adulthood. Martindell was 11 years old when he wrote this diary in Trenton, New Jersey.
In this diary Martindell records his daily activities, such as attending school, church and temperance meetings, having his boots soled, receiving a diary and sketch book with pencils, receiving and sending cards, borrowing and reading books, playing ball, meeting young women, eating ice cream and watermelon, and painting maps.