Section 2. The Congress shall have power to enforce this article by appropriate legislation.
The Twenty-Sixth Amendment lowered the voting age from 21 to 18 in federal, state, and local elections. It also gave Congress the authority to enforce the amendment through legislation.
This 1969 New Jersey campaign poster was created in support of lowering the voting age from 21 to 18, paving the way for the drafting of the 26th Amendment. However, New Jersey was one of the states that did not vote to ratify the 26th Amendment. http://www2.scc.rutgers.edu/njh/1960/vote.php
This video is a clip from the 26th Amendment Certification Ceremony. President Nixon chooses three 18-year-olds to serve as witnesses to the certification of the 26th Amendment. He does this on purpose to celebrate what the 26th Amendment does.