 After the war, he became one of the leading Radical Republicans in Congress, pressing for civil rights for former slaves and harsh treatment of former Confederates.In 1872, the same year he was elected Vice-President under Ulysses Grant, Wilson published the first volume of his "History of the Rise and Fall of the Slave Power", a severe criticism of slave owners and their primary role, according to Wilson, in bringing about the Civil War.Nelson A.