So, as much as they might have wanted to colonize Africa in the 16th, 17th, and 18th centuries, Africa's mosquitoes, microbes, and people were too much for them. So what made the difference? Technology. First, steamships made it possible for Europeans to travel inland, bringing supplies and personnel via Africa's navigable rivers. No horses? No problem. Even more important was quinine medicine, sometimes in the form of tonic water mixed into refreshing, quintessentially British, gin and tonics.