Map 5.4 Zones of Empire in Eastern North America The British zone, extending west from the Atlantic coast, was much more densely settled than the zones under French, Spanish, and Indian control. The comparatively large number of British colonists made them more secure than the relatively few colonists in the vast regions claimed by France and Spain or the settlers living among the many Indian peoples in the huge area between the Mississippi River and the Appalachian Mountains. Yet the British colonists were not powerful enough to dominate the French, Spanish, or Indians. Instead, they had to guard against attacks by powerful Indian groups allied with the French or Spanish.