Answer:
Yes, this is true. Before Europe discovered the New World they did not have potatoes, and Native Americans did not have horses. Since the natives did not have horses their hunting and transportation were severely impaired, and after the introduction of horses, the speed of their development increased significantly. Potatoes came to Europe and were a great source of food, unfortunately, Britain made Ireland grow a large number of potatoes and when the potatoes got infected the Irish population died in huge numbers. So huge that they are still recovering to this day.