From early childhood he had strong" religious feeling, and after entering Yale College in 1739, at the time of the great revival under Whitefield, his zeal led him into indiscretions. The' attitude of the College toward the "New Lights" was cold, and students had been forbidden to attend their meetings.
After leaving College he began to study theology, and on July 20th, 1742, was licensed to preach by the Danbury association of ministers. He had for some time been interested in missions, and in the autumn after he was licensed received an appointment from the society for the propagation of Christian knowledge as missionary at the Indian village of Kaunameek, twenty miles from Stock-bridge, Massachusetts.
He arrived at his post on April 1st, 1743, and labored there for a year, living in a wig-wam and enduring many hardships. After he had persuaded the Indians to move to Stockbridge and place themselves in charge of the minister there, Mr. Brainerd was ordained by the New York presbytery at Newark, New Jersey, and went to the forks of the Delaware, where he remained for about a year, making two visits to the Indians of the Susquehanna, but meeting with little success.
He next went to Crossweeksung, near Freehold, New Jersey, where his labor had a wonderful result. In less than a year he had baptized seventy-seven persons, of whom thirty-eight were adults, and the lives of most of these were permanently reformed. In 1747 Brainerd's health, exhausted by his labors, broke down completely. He had never been strong; while he was in College a severe illness had almost ended his life, and after that he suffered from consumption.
By advice of his physician, he determined to visit his friends in New England. July, 1747, found him in Northampton, Massachusetts, at the house of Jonathan Edwards, to whose daughter he was betrothed, and here he remained till his death.
Brainerd wrote an account of his labors at Kaunameek, which was published with the sermon delivered at his ordination. His journals, under the titles "Mirabilia Dei apud Indices" and "Divine Grace Displayed," appeared in 1746. His life, compiled chiefly from his diary, was written by Jonathan Edwards (1749), and a second edition, including the journals mentioned above, was edited by Serene Edwards Dwight (New Haven, Connecticut, 1822). J. M. Sherwood edited a third edition, with an introductory essay on Brainerd's life and character (Yew York, 1884). An abridgment, by John Wesley, of Edwards's life, was also published in England (2d American ed., Boston, 1821). See also Sparks's "American Biographies " and Sprague's "Annals of the American Pulpit."
(This biography was extracted from the public domain).