Dix left her unhappy home at age 12 to live and study in Boston with her grandmother. By age 14 she was teaching in a school for young girls in Worcester, Massachusetts, employing a curriculum of her own devising that stressed the natural sciences and the responsibilities of ethical living. In 1821 she opened a school for girls in Boston, where until the mid-1830s periods of intensive teaching were interrupted by periods of ill health. She eventually abandoned teaching and left Boston.
After nearly two years in England Dix returned to Boston, still a semi-invalid, and found to her amazement that she had inherited a sum of money sufficient to support her comfortably for life. But her Calvinist beliefs enjoined her from inactivity. Thus in 1841, when a young clergyman asked her to begin a Sunday school class in the East Cambridge House of Correction in Massachusetts, she accepted the challenge. In the prison she first observed the inhumane treatment of insane and mentally disturbed pe