Who is Judge Frank M. Johnson from A Testament of Hope: The Essential Writings and Speeches of Martin Luther King, Jr and what is their importance?

Judge Frank M. Johnson was a judge in the federal district court of Montgomery, Alabama. He disappointed civil rights movement leadership, when he issued an order that prevented the civil rights movement from peacefully marching from Selma to the Capital of Montgomery in an effort to gain the right to vote. The civil rights leadership was counting on federal judges to prevent unlawful interference to their rights..... rather than to participate in the interferences.