Full Text of the 15th Amendment
Section 1. 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 race, color, or previous condition of servitude.
Section 2. The Congress shall have power to enforce this article by appropriate legislation.
This amendment was designed to protect the right of African-Americans to vote and has served as the foundation for such legislation as the Voting Rights Act of 1965. Source: U.S. Senate
The Fifteenth Amendment prohibits the use of race in determining which citizens can vote and how they do so. The last of three so-called Reconstruction Era amendments ratified in the period following the Civil War, the amendment sought to abolish one of the key vestiges of slavery and to advance the civil rights and liberties of former slaves. Section 2 of the amendment gives Congress the power to enforce it by enacting federal legislation that ensures racial equality in voting.
The ratification of the Fifteenth Amendment in 1870 had little impact for almost a century because states imposed poll taxes, literacy tests, and other restrictions that kept African Americans from voting. But the passage of the Civil Rights Act of 1964 and the Voting Rights Act of 1965, along with a number of Supreme Court decisions interpreting these laws, have done much to guarantee voting rights for African Americans and other citizens of color. Source: Annenberg Classroom