Rosenberg started out in clinical practice in Saint Louis, Missouri, forming Psychological Associates with partners. In making an analysis of problems of children in school, he found learning disabilities. He wrote his first book, "Diagnostic Teaching", in 1968, reporting his findings. He also met Al Chappelle, a leader in the Zulu 1200s, a black liberation group in St. Louis. Rosenberg went to teach his approach to conflict resolution to the gang in exchange for Chappelle appearing at desegregation conventions, starting in Washington, D.C. While Chappelle was harnessing communication against racism, Vicki Legion began to collaborate to counter sexism. "I started to give my services, instead of to individual affluent clients, to people on the firing line like Al and Vicki, and others fighting in behalf of human rights of various groups."