First a brief biography
Here is a podcast on the Life of Lemuel Haynes:
Here is an exceedingly brief biography:
Born 1753 in West Hartford Connecticut, to a prominent white New England woman and an unknown black man. He spent 20 years of indenture to the Rose family in Granville, Massachusetts after being separated from his parents at five months of age.
The Rose family provided him an education and treated him like one of their children. They included him in their church attendance. Haynes’s increasingly “fearful apprehensions,” especially upon seeing the Northern Lights, which to him was a “presage of the day of judgment.” Then “one evening, being under an apple tree mourning my wretched condition …,” he wrote, “I found the Savior.”
He served as a soldier in the Continental Army.
Thereafter he served as a pastor for three separate congregations. He obtained a license to preach in 1780:
He accepted a position with a white congregation in Middle Granville and later married a young white schoolteacher, Elizabeth Babbitt. In 1785, Haynes was officially ordained as a Congregational minister.
Haynes held three pastorships after his ordination. The first was with an all-white congregation in Torrington, Connecticut, where he left after two years due to the active prejudice of several members.
His second call to the pulpit, from a mostly white church in Rutland, Vermont that had a few “poor Africans,” lasted for 30 years. 
Haynes pastored a third congregation in New York, where he died in 1833.
(Now the sermon)
(Title page of the printed copy)
A sermon delivered at Rutland, West Parish, September 4, 1798.
At the Freemen’s Meeting.
By Lemuel Haynes, Pastor of a church in Rutland.
Printed at Rutland, Vermont, by John Walker, Jr.
(The sermon includes the following two notices)
At a legal town meeting, holden in Rutland, on the first Tuesday of September 1798.
Voted, That the Selectmen of this town be requested in the name of the town, to return their thanks to the Rev. Lemuel Haynes, for his Christian and patriotic discourse, this day delivered and request a copy of the press.
Nathan Osgood, Town Clerk
The author is not insensible of the reproach to which the following publication may subject him, at the time of so great civil dissension; and has consented to have it appear abroad with a degree of reluctance. However, as all view it a detraction of their liberty, when they are not allowed with honesty and candor to speak their own sentiments; he presumes it will be sufficient defence against any imputation from those who differ with him in opinion.
The Influence of Civil Government on Religion
Psalm 11:3 If the foundations be destroyed, what shall the righteous do?
King David was raised up on high, the anointed of the God of Jacob, and the sweet psalmist of Israel. In various ways did he give evidence that he was a matter of virtue and religion. His attachment to the commonwealth of Israel, and engaged to support the laws and dignities of his country, were conspicuous ornaments of his character. Amidst the base conventions of designing men [who sought] to enervate the bands of government , assumeed the reins, and disseminate discord among the people, [– David] animated holy regard to the rights of God and man, rendered invincible to every rival. He could hear his competitors say as in verse first, Flee as the birds to your mountain; and behold the wicked than their bow, and make ready their arrow upon firing, without abandoning his country’s cause, or wantonly trifling liberties of men.
If the foundations be destroyed, which would righteous do? is a reflection worthy of the King of Israel in a time of public calamity. By foundations is generally thought to be the civil laws or government of Israel, these were invaded and threatened to be destroyed by proud and factious men, which David in the text considered as a violent attack upon religion and the good man’s cause. If the loss of authority of the land are trampled upon, what shall the righteous do? Intimating that the religious interest greatly suffer thereby.
If government be once destroyed
(That firm foundation of our peace)
And violence makes justice void,
Where shall the righteous seek redress?
The influence of civil government upon religion and morality, and their connection, is a matter to which your candid attention is called on the present occasion. That God is able to support his cause in the world without the intervention of legislative authority, and that they have no connection, is a sentiment warmly advocated by many; and indeed none can dispute them, without calling into question the power of omnipotence: but whether it be agreeable to the established constitution of heaven, in ordinary cases, to support religion without civil authority, or whether it be not favorable to virtue, is the inquiry. That God is able to appoint state officers without people’s meeting to give their suffrages, is what God has done, and has natural power to do; but none will infer from fence, that such appointment actually will take place without public exertions.
 http://www.virtualvermont.com/history/lhaynes.html. Additional sources: http://www.powerofchange.org/2010/2/15/lemuel-haynes.html – which cites to Thabiti Anyabwile, The Faithful Preacher, Recapturing the Vision of Three Pioneering African American Pastors, (Wheaton: Crossway, 2007).
 The fruit of freedom. By: Sidwell, Mark, Christian History, 08919666, 1999, Vol. 18, Issue 2. See also, http://georgewbush-whitehouse.archives.gov/kids/dreamteam/lemuelhaynes.html