Within ten years of the adoption of the Augsburg Confession (June 25, 1530), there were those who sought unity among the factions that had developed in Christendom. Notable for our purposes was Philip Melanchthon who changed the wording of the Augsburg Confession (AC) so diluting the confession of the real presence of Christ’s body and blood in the Lord’s Supper (among other things) that John Calvin was able to sign one of Melanchthon’s Variata editions. Martin Luther opposed all such efforts to effect union by weakening the true confession of the faith. As these variant forms of the AC began to circulate, the Augsburg Confession presented before Charles V in 1530 was identified as Unaltered (U.A.C.) to mark it as the original.
After Luther’s death the storm broke over the Evangelical (Lutheran) churches of Germany. Charles V conquered southern Germany and most of Northern Germany; in 1548 he held a colloquy in Augsburg where he mandated that the Lutheran churches would once again become part of the church of the Holy Roman Empire. There were those who consented to the conciliatory (union) document that Charles’ commission drew up. There were many, German princes among them, who did not. Over the next 28 years most of those who would continue to confess the U.A.C. lost everything to Charles on account of their confession, some even lost their life.
In the United States, by the middle of the 19th century, the General Synod, then the largest fellowship of Lutheran congregations, was at war with itself over whether or not to allow the changes seen in American Protestantism take hold in Lutheran congregations. In 1855 Rev. Samuel Schmucker anonymously published the Definite Platform, Doctrinal and Disciplinarian, for Evangelical Lutheran District Synods; Constructed in Accordance with the Principles of the General Synod. Commonly called simply the Definite Platform, Schmucker and others sought to end the influence of confessional Lutheranism in favor of what was termed “American Lutheranism”. But to do this it was necessary to unhinge the General Synod from the Book of Concord, especially the cornerstone document, the Augsburg Confession. The Definite Platform charges the Augsburg Confession, and those who subscribed to it, with error in its approval of the ceremonies of the mass, private confession and absolution, denial of the divine obligation of the Christian Sabbath, baptismal regeneration, the real presence of the body and blood of the Savior in the Lord’s Supper. Schmucker and his supporters rejected the descent into hell (Apostles Creed), as well as the Athanasian Creed and the other Lutheran symbols because of their length and alleged errors.
Once again, Lutherans found it necessary to confess their subscription to the Unaltered Augsburg Confession presented first in 1530 and adopted as part of the Book of Concord in 1580. While the Definite Platform was ultimately not adopted, there were enough unionizing efforts among the Lutherans that it became common for a confessional Lutheran congregations to use the designation U.A.C. as part of its name, and often on its cornerstone. To say that a congregation was U.A.C. was “shorthand” for what one could expect was confessed and taught at that congregation.
No less so today.