Historical Guide to Lutheran Church Bodies of North America
The word "synod" in American Lutheranism has been used in three ways:
Least frequently it is used to identify an ecclesiastical meeting, as for instance, "the Berkenmeyer Synod, 1735."
Most frequently the name has been used to identify an ongoing church body, as for instance, "the Missouri Synod."
In the LCA and the ELCA, however, the word refers to the geographical subdivisions that in other Lutheran bodies have been called "districts."
From the organization of the first synod, the Ministerium of Pennsylvania, by Henry Melchior Muhlenberg in 1748, to the present, there have been hundreds of "synods" organized. Some of these were organized as independent national church bodies that later created regional subordinate units; others organized as independent units and later joined together into national church bodies. As of the summer of 1991 there were twenty-two currently functioning independent church bodies in the United States and Canada that identified themselves as "Lutheran." Two of these, the Evangelical Lutheran Church in America (ELCA), 1987-, and The Lutheran Church -- Missouri Synod (LCMS), 1847-, accounted for over 90 percent of the Lutherans in North America.
--From the Forward