Pioneers of the movement
Although Stone and Campbell were to become the best-known and most influential early leaders of the movement, others preceded them and laid the foundation for their work.
The Christian Connection
The Christian churches of Smith and Jones came into contact with some of the Christian churches of James O'Kelly and found they had enough in common to join forces. This coalition, referred to as the "Christian Connection," joined up with Barton Stone and Alexander Campbell "Christians" in 1826.
Stone spent several years trying to reconcile the Christian Connection with Alexander Campbell, but distrust between Campbell and the Connection caused it to fail. Some members united with Campbell and Stone when they split off, however most of the Christian Connection merged with the Congregational Churches, which in 1957 united with other churches to become the United Church of Christ.
Church of Christ/Disciple of Christ split
In 1906 the Church of Christ split from the Disciples of Christ over many issues that run back to the Campbell-Stone Union in 1824. The two churches officially split in 1906 although the split had been building up for decades. One of the issues that lead to the split was exclusivism. Since 1836 Campell and Stone noticed a growing "furious zeal for orthodoxy". The exclusivism faction never comprised a majority within the whole of the Restoration Movement, but it did eventually dominate the Southern churches.
Although exclusivism was one of the factors involved in the split it was not the only factor. Other issues revolved around baptism, instrumental music in worship, and missionary societies also contributed to the split.
After the split The Churches of Christ became more exclusive, while the Disciples of Christ became more inclusive. The Churches of Christ became more rigid in their interpretation of the Bible, while the Disciples became less so".
Since the Church was organized as a series of independent churches loosely associated there was no method or process to handle disagreements in doctrine. Between 1920 and 1960 over 20 sects within the Church had formed. The Church of Christ had become a series of Denominations within a Denomination.
The most notable sects were;
In 1979, the Lexington Church of Christ in Lexington, Massachusetts, a struggling congregation which had shrunk to 30 or 40 members with financial problems and low morale, invited Kip McKean to become their pulpit and campus minister. McKean employed the techniques he had learned at Crossroads to spearhead a new evangelistic outreach to the Boston area college campuses. Kip McKean established many "Pillar Churches" in key metropolitan center that could in turn evangelize the cities around them. The "Boston Movement" added an additional criterion for baptism, that the individual must be a disciple prior to baptism. By 1988 members of the Church of Christ had denounced the Boston and Crossroad Movements. The final split happened in 1989 when McKean appointed nine World Sector Leaders, each responsible for a different sector of the world. A World Sector Administrator was appointed to oversee the finances of each sector. The Church of Christ sued the Boston Movement Churches for the use of the name Church of Christ. They eventually changed their name in 1994 to the "International Churches of Christ". The Crossroad Movement and Boston Movements have severed all ties with one another.
In reaction to the Crosroads movement, many Churches of Christ split from the mainline Church of Christ with their elders hiring preachers from outside the Churches of Christ and taking a more tolerant stance on other churches.