What key points does justice McLean disagree with chief justice Taney?

Justice McLean disagreed with Chief Justice Taney primarily on the interpretation of the Constitution regarding slavery and the rights of African Americans. In the Dred Scott case, Taney ruled that African Americans could not be citizens and therefore had no standing to sue, while McLean contended that free blacks could be citizens and should have legal rights. Additionally, McLean criticized Taney’s decision for its broader implications on the moral and legal status of slavery in the United States.