Polity is a fancy word for government, and in the nineteenth-century, when it came to church government, the Rev. S. J. Baird was one of the most knowledgeable men around.
Samuel John Baird was born at Newark, Ohio, in September, 1817. His parents were the Rev. Thomas Dickson Baird and Esther Thompson Baird. Samuel began his education at Jefferson College, but poor health interrupted his studies. In 1839 he took charge of a school near Abbeville, South Carolina and subsequently opened a Female Seminary [essentially a college for women] at Jeffersonville, Louisiana. Returning to college, he graduated from Central College, Danville, Kentucky, in 1843. Somehow he managed to concurrently graduate from the New Albany Theological Seminary, in Indiana, that same year.
After being licensed to preach in August of 1843 by the Presbytery of Transylvania, he devoted three years to the missionary work in the Presbytery of Baltimore, in Kentucky, and in the southwest. Then in 1846, he was ordained by Potomac Presbytery, and installed as pastor, first at Bladensburg, Maryland, and later at Georgetown, Kentucky. He also served churches in Clarksville, Tennessee and Batesville, Arkansas. During his time in that latter charge, Rev. Baird was also instrumental in laying the foundation for Arkansas College. From there, he served as pastor in Muscatine, Iowa, 1854-57 and Woodbury, New Jersey, 1857-65.
After resigning this last charge, Baird began work under a joint commission from the American Bible Society and the Virginia Bible Society, laboring as their agent in Virginia. His name first appeared on the rolls of the Southern Presbyterian Church in 1869, and he answered a call to serve as pastor of the church in Waynesboro, Virginia in 1870. For four years he served the Third Presbyterian Church in Richmond, Virginia, 1874-78, and his final pastorates were in West Virginia. The Rev. Samuel J. Baird died in Clifton Forge, Virginia on April 10, 1893.
Baird is perhaps best remembered as the author of The Assembly’s Digest, or Baird’s Digest as it most commonly known. This work is a compilation of the acts and deliverances of the Presbyterian Church in the U.S.A., covering the years 1789-1855. It is a particularly valuable work for anyone wanting a resource on the actions and history of the Presbyterian Church in the U.S.A. The full title is A Collection of the Acts,Deliverances and Testimonies of the Supreme Judicatory of the Presbyterian Church from its origin in America to the present time : with notes and documents explanatory and historical: constituting a complete illustration of her polity, faith, and history (1856). Copies of this work are rare today in print form, but thankfully it is available on the Internet, here.
Words to Live By:
Another work by Dr. Baird was a catechism, titled The Church of Christ. A sampling of questions and answers from that book follow:
Q. 261. What are the rights of individuals with reference to personal religion?
A. It is the right and duty of every individual for himself, to read and study the Word of God, and ascertain the way of salvation therein set forth ,—by faith, to lay hold of and appropriate to himself that salvation and all the promises ,—and to come before the throne of God with boldness, in the name of Christ, and independent of all human instrumentalities and mediators, and there make his confessions and offer his prayers and praises, with assurance of acceptance and salvation. 
 John 5:39; Acts 17:11; 2 Peter 1:19-21;
 Rev. 22:17.
 Rom. 10:12-13; Eph. 3:12; Heb. 10:19-22; Ps. 50:23; John 14:6; 1 Tim. 2:5.
Q. 264. What are the duties of private Christians toward others?
A. It is the duty of private Christians to be ready always to give to every one that asketh them, a reason of the hope that is in them, with meekness and fear; to watch for and use all suitable occasions to press upon the impenitent the free grace of Christ; to employ their means in relieving the temporal wants of the destitute; and, as they have opportunity, to do good to all men.
1 Peter 3:15; Rev. 22:17; Heb. 13:16; Gal. 6:10.
Q. 270. What are the principal religious duties of parents toward their children?
A. It is the duty of parents to dedicate their children to God ,—to bring them early to baptism, to teach them to know God, to pray to him, to read His Word, and to attend upon the public ordinances of the sanctuary , to exercise government and discipline upon them in love; and to bring them up in the nurture and admonition of the Lord; maintaining the stated worship of God in the house .
 Gen. 17:18; Mark 10:13-14.
 Gen. 18:19; 2 Tim. 3:14-15.
 Prov. 13:24; 22:15; Eph. 6:4; Gen. 12:7; 13:4, 18; 21:33; 35:1-4, 7; Deut. 6:7; Job 1:5.