Civilization was built on slave labor. Manchu (sic) Pichu was built by slaves, not aliens. The Chinese who built America’s railroad were, for all practical purposes, slaves. Why do you think New York City has such a great subway system? Because it was built before labor laws and OSHA. The Golden Gate Bridge. The Eerie Canal. The grand engineering projects of that era were possible because labor was cheap and expendable. It is truly amazing what humanity is able to accomplish with a little engineering know-how and a whole lot of manipulation of the underclass.
It’s a good thing not to forget this.