Given the information that we have here, we are told that the Mayans were isolated due to the mountain ranges and surrounding natural barriers. This didn't allow for good trade routes for other civilizations. Due to such isolated conditions and harsh traveling environment, any other nearby civilizations would have not wanted to risk such perils for trade. The Mayans did in fact have natural resources, as we are told here that they used stone, bone, and wood in order to aid in the construction of their cities.
Leopold II himself never step foot in the Congo during the entire time he ruled over it.
If the rubber quota was not met, then the consequence was death. The Force Publique, who was Leopold's personal police force set in the Congo, was required to collect a right hand per successful kill. hands could've been collected by FP officers, or by the villagers themselves. Since bullets couldn't be wasted, hands were sometimes chopped off while the victim was still alive. Often times, when villages were expected to pay the different with hands, they'd attack other villages to gather hands.
At least 500 Chinese labourers were imported to work on railways in the Congo, but a majority of them either left or died.
