Final answer:
Historian Frederick Jackson Turner argued that the frontier played a significant role in shaping American society and character. However, his perspective overlooked the contributions of Native Americans and other factors within the West. The frontier also served as a safety valve for overpopulation and overcivilization in Europe.
Step-by-step explanation:
The significance of the frontier in American history, as argued by historian Frederick Jackson Turner, is that it shaped the American character and influenced the development of American society. Turner saw the frontier as a meeting point between savagery and civilization, where American values of hard work and independence were nurtured. The frontier also served as a safety valve for overpopulation and overcivilization in Europe. However, it is important to note that Turner's perspective neglected the contributions of Native Americans and other factors such as families, communities, government, and commerce.