In North America the native grain was, of course, corn, which was used to make what came to be known as "johnycake" or "Indian bread"-a flatbread made of corn meal. European settlers brought wheat with them and planted large quantities of it wherever they settled. By the end of the 18th century, wheat had become the dominant grain of the continent. In this country and in England, home baking of bread continued to be common into the 20th century. (Interestingly, in France buying bread at the boulangerie seems to have been common as early as the 1600's.)
"...the standard American loaf, .... resembles in taste and feel nothing so much as damp hospital cotton."
-Karen Hess, The American Loaf: A Historical View