Complex sentence: By doing this, he escaped the horrific violence aimed at African Americans in the south during this period; even though he would continue to face racial prejudice in the north, it was not at the violent level that he faced in the South.
Split into simpler sentences: By doing this, he escaped the horrific violence aimed at African Americans in the south during this period. Though he would continue to face racial prejudice in the north, it was not at the violent level that he faced in the South.