Sentence:  Thus at the same time that William Henry Harrison was preparing to pacify the aborigines of Indiana Territory and winning fame at the battle of Tippecanoe , Anglo-Saxon settlement made a great leap into the center of the North American continent to the west of the <WSD>American</WSD> agricultural frontier . 
Meaning of the word marked with <WSD> tags:  of or relating to or characteristic of the continents and islands of the Americas