Listed are more than 200 distinct Christian bodies in the United States. As I become aware of their official web sites, they will be linked from here. This listing is based on information from Hill, Samuel S. and Mead, Frank S. Handbook of Denominations in the United States (Abingdon, 1994).
Advent Christian Church
Church of God General Conference
Amana Church Society
American Ethical Union
American Evangelical Christian Churches
American Rescue Workers
Apostolic Christian Church of America
Apostolic Faith Mission of Portland, Oregon
Apostolic Overcoming Holy Church of God
American Baptist Association
American Baptist Churches U.S.A.
Baptist Bible Fellowship, International
Baptist General Conference
Baptist Missionary Association of America
Bethel Ministerial Association
Central Baptist Association
Conservative Baptist Association of America
Duck River (& Kindred) Assns of Baptists (Baptist Church of Christ)
Free Will Baptist
General Association of Regular Baptist Churches
General Conference of the Evangelical Baptist Church, Inc.
National Baptist Convention of America, Inc.
National Baptist Convention, U.S.A., Inc.
National Missionary Baptist Convention of America
National Primitive Baptist Convention of the U.S.A.
North American Baptist Conference
Progressive National Baptist Convention, Inc.
Separate Baptists in Christ (General Association of Separate Baptists)
Seventh Day Baptist General Conference
Southern Baptist Convention
United Free Will Baptist
Berean Fundamental Church
Bible Fellowship Church
Bible Protestant Church
Bible Way Church, Worldwide
Brethren Church (Ashland)
Brethren in Christ Church
Church of the Brethren
Church of the United Brethren in Christ
Fellowship of Grace Brethren Churches
Old German Baptist Brethren
United Zion Church
Byzantine Catholic Church in America
Liberal Catholic Church, The
Mariavite Old Catholic Church
North American Old Roman Catholic Church
Old Roman Catholic Church (English Rite)
Polish National Catholic Church of America
Roman Catholic Church
Christian and Missionary Alliance
Christian Catholic Church
Christian Church, The (The Stone-Campbell Movement)
Christian Church (Disciples of Christ)
Christian Churches and Churches of Christ
Churches of Christ
Christian Church of North America, General Council
Christian Congregation, Inc.
Church of Christ (Holiness) U.S.A.
Church of Christ, Scientist
Church of God
Church of God, The (Huntsville, Alabama)
Church of God, Inc.,The (Original)
Church of God (Anderson, Indiana)
Church of God (Cleveland, Tennessee)
Church of God (Seventh Day)
Church of God and Saints of Christ
Church of God by Faith, Inc.
Church of God in Christ
Church of God in Christ (International)
Church of God of Prophecy
Church of God, Holiness
Church of Jesus Christ
Church of Our Lord Jesus Christ of` the Apostolic Faith, Inc.
Churches of Christ in Christian Union
Churches of God, General Conference
Churches of Illumination
Churches of the Living God
Community Churches, International Council of
Congregational Bible Churches, Inc.
Congregational Christian Churches (National Association)
Congregational Holiness Church
Conservative Congregational Christian Conference
African Orthodox Church, The
Anglican Orthodox Church
Episcopal Church, The
Reformed Episcopal Church
Other Anglican Bodies in the United States
Evangelical Church, The
Evangelical Congregational Church
Evangelical Covenant Church, The
Evangelical Free Church of America
Foursquare Gospel, International Church of the
Friends General Conference
Friends United Meeting (Five Years Meeting)
Religious Society of Friends (Conservative)
Grace Gospel Fellowship
Independent Fundamental Churches of America
American Lutheran Church, The
Apostolic Lutheran Church of America
Church of the Lutheran Brethren
Church of the Lutheran Confession
Evangelical Lutheran Church in America
Evangelical Lutheran Synod
Free Lutheran Congregations, The Association of
Lutheran Church--Missouri Synod, The
Lutheran Church in America
Protestant Conference (Lutheran)
Wisconsin Evangelical Lutheran Synod
Beachy Amish Mennonite Churches
Church of God in Christ, Mennonite
Conservative Mennonite Conference
Evangelical Mennonite Church
Fellowship of Evangelical Bible Churches
General Conference Mennonite Church
Mennonite Brethren Churches, General Conference
Old Order Amish Church
Old Order (Wisler) Mennonite Church
Reformed Mennonite Church
African Methodist Episcopal Church
African Methodist Episcopal Zion Church
Christian Methodist Episcopal Church
Congregational Methodist Church
Evangelical Methodist Church
Free Methodist Church of North America
Primitive Methodist Church, U.S.A.
Reformed Methodist Union Episcopal Church
Southern Methodist Church
Union American Methodist Episcopal Church
United Methodist Church, The
Metropolitan Community Churches, Universal Fellowship of
Moravian Church (Unitas Fratrum)
Unity of the Brethren
Church of Christ (Temple Lot)
Church of Jesus Christ (Bickertonites)
Church of Jesus Christ of Latter-Day Saints, The
Church of Jesus Christ of Latter-Day Saints (Strangite)
Reorganized Church of Jesus Christ of Latter-Day Saints
Apostolic Christian Church (Nazarene)
Church of the Nazarene
New Apostolic Church of North America
Open Bible Standard Churches, Inc.
Albanian Orthodox Archdiocese in America
American Carpatho-Russian Orthodox Greek Catholic Church
Antiochian Orthodox Christian Archdiocese of North America
Bulgarian Eastern Orthodox Church
Greek Orthodox Archdiocese of North and South America
Orthodox Church of America
Romanian Orthodox Episcopate of America
Russian Orthodox Church
Serbian Eastern Orthodox Church in the U.S.A. and Canada
Syrian Orthodox Church of Antioch
The Ukrainian Orthodox Church of the U.S.A.
Assemblies of God, General Council of .
Independent Assemblies of God, International
International Pentecostal Church of Christ
Pentecostal Assemblies of the World, Inc.
Pentecostal Church of God
Pentecostal Free-Will Baptist Church, Inc.
Pentecostal Holiness Church, International
United Pentecostal Church, International
Pillar of Fire
Associate Reformed Presbyterian Church .
Bible Presbyterian Church
Cumberland Presbyterian Church
Evangelical Presbyterian Church
Orthodox Presbyterian Church
Presbyterian Church in America, The
Presbyterian Church (U.S.A.)
Reformed Presbyterian Church of North America .
Second Cumberland Presbyterian Church in the United States
Christian Reformed Church in North America
Hungarian Reformed Church in America
Netherlands Reformed Congregations
Protestant Reformed Churches in America
Reformed Church in America.
Reformed Church in the United States
National Spiritual Alliance of the U.S.A.
National Spiritualist Association of Churches
Swedenborgian Church, General Convention of
Triumph the Church and Kingdom of God in Christ (International)
Unitarian Universalist Association
United Church of Christ
United Holy Church of America, Inc.
Unity School of Christianity
Volunteers of America, Inc.
Wesleyan Church, The
Worldwide Church of God