The supreme court also decided in Dred Scott v. Sandford that people of African descent imported into the United States and held as slaves were not included under the constitution and could never be citizens.

The supreme court was wrong on racism, and it's wrong on corporate personhood.

What's right and wrong is a purely human construct and changes over time. The point was that, currently, in the eyes of the law, corporations hold many of the same rights as individuals. This could change, but would require special circumstances not considered previously or a change to the law by congress.