Karl Heinrich Wilhelm Wackernagel was born in Berlin on 23 April 1806. His father, a police officer, died in 1815; three years later his mother died. Wackernagel and his sisters, Friederike and Luise, and their brothers, Philipp and Karl--all older than he--were placed under the guardianship of a former colleague of their father's named Gemmel. Philipp and Karl dropped out of school to support the family; Friederike and Luise helped out by doing artistic embroidery. Wackernagel's brothers and sisters were unanimous in their resolve to make it possible for him to finish high school; they were convinced that he was the most gifted of the siblings.

During his early teens Wackernagel, like many of his friends, became heavily involved in the political upheavals following the defeat of Napoleon. Friedrich Ludwig Jahn, who had gained fame for his efforts to improve national education and to launch far-reaching programs in physical training, captivated...