The amendments that lowered the voting age to eighteen and gave women the right to vote were

The Nineteenth Amendment and the Twenty-sixth Amendment The 19th Amendment gave women the right to vote. The 26th Amendment lowered the voting age from 21 to 18.

Context/details:

19th Amendment

The 19th Amendment to the Constitution reads as follows:

The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex. Congress shall have power to enforce this article by appropriate legislation.

The proposal to add such an amendment was first introduced in Congress in 1878, but Congress did not pass the amendment till 1919 - - after the experience of women taking on greater roles in the country during the First World War. The amendment achieved ratification by a sufficient number of states and was added to the Constitution by August, 1920.

26th Amendment

During the 1960s in America, protests against the Vietnam War were active on college campuses across the country. Part of those protests were the demands of young people chanting, "Old enough to fight, old enough to vote." Since 18 was old enough to be drafted to fight in the war, young people argued for their right to vote as full citizens.

The 26th Amendment was passed by Congress on March 23, 1971. It was ratified by the states faster than any other amendment, achieving ratification by July 1, 1971.

The 26th Amendment is worded as follows:

Section 1. The right of citizens of the United States, who are eighteen years of age or older, to vote shall not be denied or abridged by the United States or by any State on account of age. Section 2. The Congress shall have the power to enforce this article by appropriate legislation.

The 19th Amendment gave women the right to vote and the 26th Amendment gave 18 year olds the right to vote.