MAP 3.3 Ethnic and Racial Diversity in British North America, 1750 By 1750 British North America was a far more diverse region than it had been fifty years earlier. In 1700 the English dominated most regions, while the Dutch controlled towns and estates in the Hudson River valley. By 1750, however, growing numbers of African Americans, German and Scots-Irish immigrants, and smaller communities of other ethnic groups predominated in various regions.