Final answer:
In 1770, the German population had the largest settlement in the United States.
Step-by-step explanation:
In 1770, the ethnic group with the largest settlement in the United States was the German population. According to U.S. Census Bureau records, the number of Germans living in the country during the second half of the nineteenth century exploded. On the other hand, the ethnic group with the smallest settlement in 1770 cannot be determined from the given information.