Collin McKinney, land surveyor, merchant, politician, and lay preacher, was born on April 17, 1766, in Hunterdon County, New Jersey, second of ten children of Daniel and Massie (Blatchley) McKinney (many variants of his mother's names occur in the sources). Early in the 1770s he migrated with his family to Virginia. In these early years the family was on the move, and later McKinney helped to provide for the family while his father was fighting the British in the Revolutionary War. Consequently he had no opportunity for formal schooling. After the war he and his family moved to an outpost established by a cousin in 1788 in what later became Lincoln County, Kentucky. In 1792 he married Annie (Amy) Moore, with whom he had four children. After her death he married Elizabeth Leek Coleman, in 1805, and had six children with her. From 1818 to 1821 McKinney managed the vast Tennessee estates of Senator George W. Campbell, who was serving as minister to Russia. While in Tennessee, McKinney operated a trading post, but he soon gave it up and returned to Kentucky, where he settled in Elkton, Todd County. Then he migrated with his family and many McKinney relatives to Hempstead County, Arkansas Territory, a few miles below Fulton. When this area became Lafayette County, Arkansas, in 1827, he was elected justice of the peace.
In 1826 McKinney became a friend of Benjamin R. Milam, agent for introducing settlers into Arthur G. Wavell's Red River colony in Northeast Texas, a possession of Mexico also claimed by the United States as Miller County, Arkansas. Impressed by the generous land grants offered to settlers in the Wavell colony and fully aware that it was in disputed territory, McKinney and most of his relatives had by 1830–31 signed contracts with Milam and located their new surveys. Until the beginning of the movement for Texas independence, the McKinney family, like other settlers, chafed under the authority of two opposed governments. They paid taxes, served on juries, and held county offices in Miller County, Arkansas, and in the same year petitioned the Mexican government at Nacogdoches for redress of grievances. McKinney was one of five delegates from Red River to the Convention of 1836 at Washington-on-the-Brazos. He was one of five appointed to the committee to draft the Texas Declaration of Independence, and as the oldest member of the convention, at seventy, he was given the pen after the signing. He was also a member of the committee that produced the Constitution of the Republic of Texas, and later he was elected a delegate from Red River County to the First, Second, and Fourth congresses of the republic. In 1840 he joined other family members who earlier had moved to that part of Fannin County which became Grayson and Collin counties. Collin County and McKinney, the county seat, were named in his honor. He is credited with insisting that as new counties were delineated in North Texas, the boundaries should be straight.
McKinney was associated with several frontier churches. First, he was a deacon in a Separate Baptist church near Crab Orchard, Kentucky, where his father moved in 1780. In 1817 McKinney united with Barton W. Stone's Christian movement, and although there is no mention of a church where he first lived in Texas, he frequently exhorted at religious meetings, and worship was conducted in his home. The church at Hickman's Prairie was organized in 1842 with McKinney and his son William C. as elders. McKinney was also a member of a church at Mantua, a congregation established by an immigrant preacher, J. B. Wilmeth, in 1846. Members of the Church of Christ consider McKinney a "Christian patriarch." During his lifetime he was a subject of six different governments: England, Virginia, the United States of America, the Republic of Mexico, the Republic of Texas, and the Confederate States of America. He died on September 9, 1861, at his home in Collin County and was buried at Van Alstyne.