After the Civil War, the 15th Amendment gave the right to vote to all male US Citizens.
However, some communities refused to allow certain minorities to vote.
Women could not vote until the 19th Amendment (1920).
The Chinese Exclusion Act which took away the right to vote from US native-born citizens of Asian ancestry was repealed in 1943.
Jim Crow laws in the Southern United States which strongly discouraged African-Americans to vote was repealed by the 24th Amendment, 1964 & the Voting Rights Act 1965.Here is a pdf of Voting Rights.
Here is a pdf of Voting Cloze Essay.
To read, listen, and watch more about the presidential election, go to VOANews USA Votes 2008.