While most Americans count Abraham Lincoln among the most beloved and admired former presidents, a dedicated minority has long viewed him not only as the worst president in the country's history, but also as a criminal who defied the Constitution and advanced federal power and the idea of racial equality. In Loathing Lincoln, historian John McKee Barr surveys the broad array of criticisms about Abraham Lincoln that emerged when he stepped onto the national stage, expanded during the Civil War, and continued to evolve after his death and into the present.

The first panoramic study of...