Dalton was born on approximately September 5, 1766, in Eaglesfield, England. Since his Quaker parents did not register his birth officially, no one knows his exact birth date.

Strongly influenced by his Quaker faith, Dalton grew up in modest surroundings and continued to live simply throughout his life. He attended the local school at Eaglesfield until the age of 11. A year later, he returned as a teacher at the same school, confronted with the task of instructing a number of students his own age or older. Then, as throughout his life, Dalton continued studying a number of topics on his own.

At the age of 15, Dalton became an assistant at the Quaker school in Kendal. About four years later, he was appointed principal of the school, a post he held for eight more years. While at Kendal, Dalton also offered a series of public lectures on natural philosophy. The series...