Thoreau graduated from Harvard in 1837 and returned to Concord. Without explanation, he reversed the order of his first and middle names, signing himself "Henry David" instead of "David Henry" for the rest of his life. He taught public school for a short time (two weeks) in 1837. His disinclination to use physical punishment did not sit well with the Concord School Committee. Disgusted, Thoreau arbitrarily applied the rod to six students and promptly resigned. Unable to find another teaching job, he devoted himself to his father's pencil-making business.
In October of 1837, Thoreau began to keep a journal in which he made regular entries, recording his daily experiences, thoughts, observations of nature and of life, and reactions to reading. His journals, which he kept until 1861, became the source of much of his published writing. In a real sense, they form his magnum opus. Moreover, on April 11, 1838, Thoreau delivered his first lecture before the Concord Lyceum (the lecture "Society," based on journal entries that he had made in March of 1838). The lecture platform provided Thoreau with another means of expressing his developing thoughts prior to their reworking for publication. In Thoreau's writing, as in Emerson's, there is frequently a close relationship between journal, lecture, and published word.
In 1838, still unable to find work as a teacher, Thoreau opened a private school, running it first in his family's house, then in the Concord Academy building, which he rented when the Academy lost its schoolmaster. Thoreau took over the existing name as well as the building. The school was open to boarding and day students, the boarding students staying in the Thoreau family home. As the enrollment increased, Thoreau added his brother John to the teaching staff of one. Most of the pupils were from Concord and the immediate vicinity. A few, like Edmund Sewall of Scituate, Massachusetts, came from farther away. The curriculum included English, Latin, Greek, French, mathematics, physics, and natural history. The students engaged in hands-on learning, made frequent field trips, and focused considerable attention on nature. The Thoreau brothers shunned physical punishment. Successful though the school was, John's declining health forced its closing in 1841.
