Answer:
The 26th Amendment to the U.S. Constitution sets the voting age at 18. (Prior to ratification of the Amendment in 1971, most Americans had to be at least 21 to vote.)
Step-by-step explanation:
But honestly, I think that adults just think because teenagers are younger, their brains are still developing, and they don't think teenagers should be allowed to vote.
“Demonstrating is not the same as voting, which requires a high level of civic responsibility and knowledge,” said David Davenport, a researcher at the Hoover Institution at Stanford University in California.