The following essay disputes what you say:
The Religious Affiliation of
Alexander Campbell
Co-Founder of the Stone-Campbell Restoration Movement within American Protestantism
Alexander Campbell's family background was Presbyterian (they were from Scotland), but he and his father became Baptists in 1812. Campbell became a popular Baptist preacher and editor of a widely circulated paper, The Christian Baptist. Rejecting a variety of elements in the Baptist churches of his time, Campbell later formed the Churches of Christ denomination. Campbell rejected infant baptism and confessions of faith, especially the Philadelphia Confession of Faith (1742). Campbell's maxim was "Where the Bible speaks, we speak; where the Bible is silent, we are silent."
From: Timothy George, "Southern Baptist Ghosts" in First Things No. 93 (May 1999): pages 17-24 (
http://www.firstthings.com/ftissues/ft9905/george.html; viewed August 1999). [This essay is adapted from a lecture presented to the St. George Tucker Society at Emory University. The author is Dean of Beeson Divinity School, Samford University, and Senior Editor at Christianity Today]:
R. B. C. Howell (1801-1868) was one of the founders of the SBC [Southern Baptist Convention] in 1845. He served four terms as president of the Convention and was also pastor of the First Baptist Church of Nashville. Near the end of his ministry, he reviewed the history of Baptists in Tennessee and described the devastation wrought by these three movements:
Now for the third time within forty years, the desolation of Baptist churches in Tennessee was complete. They were first rent, overthrown, and destroyed by the violence of the controversy on the doctrine of predestination; they were secondly crushed and scattered by the "Reformation" of Mr. [Alexander] Campbell; they were thirdly severed and prostrated by the Landmark controversy. Scarcely had they begun to recover from one calamitous division when they fell into another. Will the Baptists of Tennessee ever be united, and labor together continuously in the cause of Christ?
The movements Howell mentioned were all led by powerful personalities, but they also dealt with basic issues of Baptist identity and Christian faith: namely, the balance of Scripture and tradition as norms of belief and practice (Campbellism); the nature of the true church and its identity markers (Landmarkism); and the reality of divine grace in the plan of salvation (hyper-Calvinism)...
Alexander Campbell was born in Ireland, educated in Scotland, and emigrated to Pennsylvania with his father, Thomas Campbell, where both were immersed as believers and affiliated with the Baptist denomination in 1812. The Campbells were Scotch-Irish Presbyterians by background, but after Alexander's wife, Dorothy, gave birth to their first child, they rejected infant baptism. Campbell was a popular speaker at Baptist gatherings and disseminated his ideas through a widely circulated paper he edited called the Christian Baptist.
The Campbell movement (the word "Campbellite" was a nickname coined in 1832) began as an effort to counteract the disunity of Christendom. Campbell's reforming movement was part of the larger restorationist impulse in American Protestantism. Campbell wanted to bring visible unity among all Christians and hence "restore" the true church by returning to the New Testament, which, he believed, contained a precise blueprint for church order and belief. Building on the earlier restorationist call of Barton W. Stone, Campbell led many erstwhile Baptists to leave their congregations and affiliate with his newly formed Churches of Christ.
The results of this schism are with us still; it is not uncommon to find Baptist and "Christian" [i.e., Stone-Campbellite] churches still facing one another across town squares and village lanes throughout Tennessee and Kentucky... Why did Campbell leave the Baptists after seventeen years of ministry among them? For one thing, Campbell's stark biblical literalism led to disagreements over many aspects of church life and ministerial order. Campbell opposed, for instance, the use of instrumental music in worship and refused to call ministers by officious-sounding titles such as "Reverend" or "Doctor."
Campbell also had serious soteriological differences with the Baptists. He taught a doctrine that sounded very much like baptismal regeneration, denying the direct agency of the Holy Spirit in conversion. Indeed, Campbell would often poke fun at Baptists who talked about "getting religion" or being convicted of sin and drawn to Christ by the work of the Spirit. For Baptist awakeners in the tradition of Jonathan Edwards, George Whitefield, and the Wesleys, this smacked of heresy or even blasphemy, ruling out what the Baptists called "an immediate work of God's grace in the heart."
A still more serious breach between Campbell and his Baptist cohorts stemmed from his outright rejection of confessions of faith. Campbell viewed religious authority according to a simple maxim: "Where the Bible speaks, we speak; where the Bible is silent, we are silent."
...By the nineteenth century, Baptists had produced many... confessions, but the one against which Campbell directed most of his ire was the Philadelphia Confession of Faith, a document printed for the Philadelphia Baptist Association by Benjamin Franklin in 1742. By the 1830s it exerted a magisterial influence among Baptists North and South. At the founding meeting of the Southern Baptist Convention in 1845, each of the 293 "delegates," as they were then called, who gathered in Augusta, Georgia, belonged to churches that embraced this confessional standard.
Although he was the most important opponent of confessions of faith, Campbell was not the first Baptist to oppose their use...
By the time of Campbell's death in 1866, Baptists and the Restorationists had already gone their separate ways. Yet the lingering influence of Campbell's legacy would continue to haunt Southern Baptists...
Baptists of the nineteenth century also rejected Campbell's strong anti-confessionalism. In the early part of the twentieth century, however, the ideal of American individualism was wedded to the Baptist concept of "soul competency" resulting in the triumph of what Ralph Waldo Emerson called "the infinitude of the private mind." Many contemporary Baptists would be surprised to learn that venerable shapers of the Baptist tradition such as Andrew Fuller, Richard Furman, B. H. Carroll, and even E. Y. Mullins often spoke in an affirming way of "the Baptist creed."
...It is ironic that Campbell's slogan, "No creed but the Bible," has become a shibboleth of Baptist identity among many of the denominational descendants of those who stoutly opposed it in Campbell's day.
http://www.adherents.com/people/pc/Alexander_Campbell.html