The controversial defendants he represented included civil rights activist Robert F. Williams and Black Panther leader H. Rap Brown.

[3][6] Sixteen civil rights activists, eight of them black and eight of them white, boarded Greyhound and Trailways buses and traveled through Virginia, North Carolina, Kentucky, and Tennessee to bring public attention to the reality of racial segregation and dramatize the South's widespread disregard of the 1946 U.S. Supreme Court decision Irene Morgan v. Commonwealth of Virginia.

After being released on bail in Richmond, Lynn traveled to Raleigh, North Carolina, where he joined his colleagues on the bus and completed the journey.

[3][7] The National Association for the Advancement of Colored People (NAACP) could not enlist any of its attorneys to represent the boys and referred the case to Lynn.

[7] As a result of these efforts and international attention that Lynn and others generated for the case, which was embarrassing for the US government, after three months' detention the boys were pardoned by the governor of North Carolina and released.

In the appeal filed in 1965, Lynn and Kunstler asked for the convictions to be overturned on the grounds that the Six had not had competent legal counsel for their trial.

After another trial was held, again ending in a mistrial, the defendants were allowed to plead guilty to manslaughter in exchange for their immediate release from confinement.

[3][13] Conrad Lynn's decision to handle his brother's case was contrary to the advice of civil rights organizations such as the NAACP, which considered support of the U.S. war effort to be in the best interest of African Americans.

Socialist Party leader Norman Thomas and journalist Dwight Macdonald led a support effort under the name 'Lynn Committee to End Discrimination in the Armed Forces.'

Winfred Lynn's case was based on a contention that racial discrimination in the military violated the Selective Service Act of 1940.

He did not prevail in that case; the court's ruling in 1971 rejected all three arguments that had been advanced in support of selective conscientious objection.

[3] In the 1950s, he successfully defended Ruth Mary Reynolds against the charge of collaboration with the Puerto Rican Nationalist movement in the alleged advocacy of the overthrow the U.S.

He speculated that the committee's calling him reflected an effort by them "to frighten integrationists who are more radical than Martin Luther King.