The largest African-American Pentecostal Group is the Church of God in Christ (COGIC), headquartered in Memphis, TN. The formative leader of the Church of God in Christ was Charles Harrison Mason (1866-1961), son of slave parents.
The Church of God in Christ was on record in WWI as a pacifist denomination. C. H. Mason, was surveilled, arrested, jailed, and threatened numerous times for his teaching and encouraging of African Americans to refuse to kill in war and to choose conscientious objection instead when drafted.
Here is some of what the Church of God in Christ taught its members about violence and warfare.
Of Magistrates and Civil Governments.
We believe that civil magistrates are ordained for the peace, safety, and good of the people. That it is our duty to pray for them, and obey them in all things which is not contrary to the word of God, and that does not take authority over, or force the conscience in matters of bearing arms or going to war. That it is our duty to honor them, pay tribute, to respect them in all lawful requirements of civil government.
Examples of Church of God in Christ Conscientious Objectors in WWI
Ozro Thurston Jones, COGIC WWI Draft Registration
Arthur C Driscoll, COGIC WWI Draft Registration Card
Notice that Orzo Jones and Arthur Driscoll, both African-Americans, gave their reason for exemption from military service as “religious belief” and “religious reasons.” They were claiming conscientious objection to military service, based upon membership in a religious sect on record against members going to war, specifically as members of the Church of God in Christ.