Returning from the war, Lemuel engaged in agriculture; but he had early been given a pious trend and soon decided to study theology in anticipation of the designs of Providence concerning him. For some time he had been accustomed to read the Bible and sermons of others on the occasions of conducting family prayers in the home of David Rose. From this exercise he mustered sufficient courage to read one of his own sermons, and finally to preach before the local congregations, which marveled at the power of his words. To prepare himself thoroughly to preach, Haynes once planned to attend Dartmouth College, but shrank from it. After studying privately under Daniel Farrand of Canaan, Connecticut, and William Bradford of Wintonbury, Haynes spent a short period teaching a school for whites. He was licensed to preach in the Congregational Church in 1780 and was ordained soon thereafter, beginning his ministry at Middle Granville, where he labored five years. Here Bessie Babbit, a white woman of considerable education and piety, offered him her heart and they were married in 1783.

From this small charge Haynes was called to Torrington, Connecticut. A leading citizen was much displeased that the church should have a "nigger minister," and to show his lack of respect for the new incumbent this man went into the church and sat with his hat on. "He had not preached far," said the man, "when I thought I saw the whitest man I ever knew in that pulpit, and I tossed my hat under the pew." Haynes was then called to take charge of the Congregational Church in West Rutland. Here his usefulness was appreciated and his efforts were extended to other towns through his revivals, one of the most successful of which he conducted in Pittsfield. Having developed such power, he was employed, in 1804, by the Connecticut Missionary Society to labor in the destitute sections of Vermont. In 1809 he was appointed to a similar service by the Vermont Missionary Society. In 1814 he preached extensively in Connecticut, appearing before crowded houses, having in his audience on one occasion President Dwight of Yale.

With such standing in the church Haynes was expected to manifest interest in the great questions at issue in New England. One of these was the Stoddardian principle of admitting moral persons without credible evidences of grace, to the Lord's Supper, and the half-way covenant by which parents though not admitted to the Lord's Supper were encouraged to offer their children in baptism. In this debate Haynes, with his eloquence and logic, vanquished the famous Hosea Ballou by his powerful sermon based on the text Ye shall not surely die. There was also a difference of opinion with respect to the operations of the Holy Spirit, but Haynes stood with Edwards and Whitefield. Being thus active in dispelling clouds of doubt, he brought many back to a more righteous conduct.

Becoming involved in the partisan strife which characterized the rise of political parties after Washington's inauguration, Haynes alienated the affections of some of his communicants by his bold advocacy of the principle conducive to a strong national government as administered in the beginning by George Washington, whose policies Haynes admired. He then left West Rutland and preached a while in Manchester, Vermont, until 1822, when he accepted a call to Granville, New York. There he spent usefully the last eleven years of his life.

In spite of the fact that Lemuel Haynes was working altogether among white people, however, he was successful wherever he was stationed. His eloquence and Christian nobility won him much attention. "He always showed himself a man of a feeling heart, sensibly affected by human suffering," says Cooley, his biographer. "At home he was industrious, his family government was parental. He was the embodiment of piety and honesty." Churches and associations were strengthened by his labors. Their membership increased and the influence of the gospel was extended. So lived and died one of the noblest of the New England Congregational ministers of a century ago. Of illegitimate birth, and of no advantageous circumstances of family, rank or station, he became one of the choicest instruments of Christ. His face betrayed his race and blood, and his life revealed his Lord.

There served as a pioneer worker for the Presbyterians John Gloucester, who founded the first African Presbyterian Church in Philadelphia in 1807. According to Gillett's History of the Presbyterian Church in the United States, this church owed its existence, and for many years its continued support, largely to the "Evangelical Society of Philadelphia," organized upon the recommendation and influence of Dr. Alexander. "Its first pastor, although never installed," says Gillett, "was John Gloucester, a slave of Dr. Blackburn of Tennessee. He had attracted the attention of the latter, under whose preaching he was converted, by his piety and natural gifts, and by him was purchased, and encouraged to study with a view to the ministry. After having been licensed and ordained by the Union Presbytery, he was, in 1818, received from that body by the Philadelphia Presbytery, and, under the patronage of the 'Evangelical Society,' continued in charge of the African Church until his death in 1822. The house of worship, located on the corner of Shippen and Seventh Streets, was completed in 1811."

"Mr. Gloucester first commenced his missionary efforts by preaching in private houses," continues Gillett, "but these were soon found insufficient to accommodate his congregations. A schoolhouse was procured near the site of the future edifice; but in clear weather he preached in the open air. Possessed of a strong and musical voice, he would take his stand on the corner of Shippen and Seventh Streets, and while singing a hymn would gather around him many besides his regular hearers, and hold their attention till he was prepared to commence his exercises. Possessed of a stout, athletic frame, and characterized by prudence, forbearance, and a fervent piety, he labored with unremitting zeal, securing the confidence and respect of his brethren of the Presbytery, and building up the congregation which he had gathered. His freedom was granted him by Dr. Blackburn, and by his own application he secured the means in England and this country to purchase his family. He is said to have been a man of strong mind, mighty of prayer, and of such fervor and energy in wrestling supplication that persons sometimes fell under his power, convicted of sin."

To this class of Negro preachers in the South belongs John Chavis, mentioned in another connection below. Chavis was a full-blooded Negro of dark brown color, born probably near Oxford, Granville County, North Carolina, about 1763. From a youth he impressed the public as a man of unusual power and was, therefore, sent by his friends to Princeton to see if a Negro could take a collegiate education. Some have said that he was never a regularly enrolled student at Princeton. The records, however, show that he was under the direction of Dr. Witherspoon, who was soon convinced that the experiment "would issue favorably." In keeping with the course of study of that time, he was chiefly interested in the classics. In these fields he easily took rank as a good Latin and a fair Greek scholar. Exactly how much work he did in the field of theology is not known, but as the line drawn between theology and classical studies at that time was not very definite, he could easily lay a foundation for work in the ministry, and especially so if his instruction were under the direction of one man, who would shape his course of study in keeping with his practical needs rather than in conformity with the formal training of the school.

Whether Chavis was sent to Princeton to make a minister of him or not, however, he very soon bestirred himself in that direction. From Princeton he went to Lexington, Virginia, to preach. In the records of the Presbyterians for 1801, Chavis is referred to as "a black man of prudence and piety." "For his better direction in the discharge of duties which are attended with many circumstances of delicacy and difficulty" some prudential instructions were issued to him by the General Assembly, "governing himself by which the knowledge of religion among the Negroes might be made more and more to strengthen the order of the society." The annals of the year 1801 report him in the service of the Hanover Presbytery as a "riding missionary under the direction of the General Assembly." He was very soon stationed in Lexington as a recognized preacher of official status working among his own people. In 1805, however, he returned to his native State, where as a result of the close relations existing between the whites and blacks and his power as an expounder of the gospel, he preached to large congregations of both races.

Referring to his career, Paul C. Cameron, a son of Judge Duncan of North Carolina, said: "In my boyhood life at my father's home I often saw John Chavis, a venerable old Negro man, recognized as a freeman and as a preacher or clergyman of the Presbyterian Church. As such he was received by my father and treated with kindness and consideration, and respected as a man of education, good sense and most estimable character." Mr. George Wortham, a lawyer of Granville County, said: "I have heard him read and explain the Scriptures to my father's family repeatedly. His English was remarkably pure, containing no 'Negroisms'; his manner was impressive, his explanations clear and concise, and his views, as I then thought and still think, entirely orthodox. He was said to have been an acceptable preacher, his sermons abounding in strong common sense views and happy illustrations, without any effort at oratory or sensational appeals to the passions of his hearers."