What started the conflict in A Battle from the Start?

A Battle from the Start: The Life of Nathan Bedford Forrest is a biography of the controversial Civil War leader. Almost all of Forrest's life was—in a sense—a conflict.
Born into a poor blacksmith's family in 1821, he had to overcome the early death of his father and his lack of formal education. He succeeded in supporting his family. Then Forrest became an extremely rich cotton planter and slave trader.
When the Civil War started in 1861, he enlisted as a private. However, his wealth and military skill led to his promotion. His Civil War record was brilliant, as he constantly fought—and usually defeated—much larger Union forces.
After the war ended in 1865, he returned to business. He could no longer sell slaves, so he was not nearly as successful as in the years before the war. He died in 1877.
In addition to fighting for economic and military success, Forrest also had to fight for his reputation. He was heavily criticized for the Fort Pillow massacre of black soldiers during the war. Also, he was attacked for his role in the Ku Klux Klan after the war.
The conflicts surrounding Forrest's legacy continue to this day. He remains a very controversial and divisive figure. For instance, in 2017, a statue of Forrest was removed from a park in Memphis, Tennessee.