Which group of people was most directly affected by the twenty-sixth amendment

People with Eighteen years of age, is the right answer.

Explanation:

Amendment Twenty-sixth to the Constitution of the United States is very significant in the history of constitutional amendments of the United States. This Constitutional Amendment lowered the minimum voting age. Following this amendment, the voting age of American citizens was reduced to 18 from 21. Moreover, this Amendment prevents the federal and the state government from employing age as a reason for rejecting the right to vote to any of the U.S. citizens who is at least 18 years of age.

roosevelt believed that in light of the country's recent military successes, it was unnecessary to use force to achieve foreign policy goals, so long as the military could threaten force. this belief, and his strategy of “speaking softly and carrying a big stick,” shaped much of roosevelt's foreign policy.