By the turn of the 20th century, the population of the US had shifted to three large racial and ethnic groups. These groups are:a) African-Americans, Hispanics, Caucasiansb) Asians, African-Americans, Caucasiansc) Asians, African-Americans, and Hispanicsd) African-Americans, Native American Indians, Caucasianse) Hispanics, Native American Indians, Caucasians

The correct answer is A. By the turn of the 20th century, the population of the US had shifted to three large racial and ethnic groups, which are African-Americans, Hispanics, and Caucasians.

Explanation:

The white population constitutes the majority of American citizens. Its percentage is close to 80% of the total population. White Americans are the overwhelming majority in the Midwestern States such as South Dakota, North Dakota, Nebraska, Wyoming, Idaho, Iowa and Montana, and New England. Most white are of German (16.8%), Irish (12.1%), English (9.3%), Italian (5.9%), Polish (3.3%), French (3.2%), Jewish (2.2%), and Scottish (2%) descent.

Over 15% of the population is Hispanic, dominating in southwestern states such as California, Arizona, New Mexico, and Nevada. Hispanics are already the largest minority group in America.

Almost 13% of Americans are of African descent. Blacks are the largest minority in eastern and southern states such as Alabama, Georgia, Louisiana, Mississippi, and also New York.

Asians account for 4.5% of US citizens. The population of Asian origin mainly resides in large cities and in the states of California and Hawaii.

Native Americans today make up less than 1% of all Americans. The smallest ethnic group in the US are Hawaiians and Pacific Islanders, who constitute 0.2% of the population.