Sherman used "absolute warfare" I believe. He is most famous for his March to the Sea in which he marched his men through Georgia and literally destroyed everything in his path. This is known as being very brutal because he mostly destroyed civilian property. The southerners reaction was shock, as they couldn't believe such brutal tactics were being used. Sherman's tactic was successful nonetheless. Challenges faced by freedmen were the inability to own land and lack of citizenship. The Freedman's Bureau was meant to help freed slaves get on their feet essentially.