Discussed in this essay:

Give Us the Ballot, by Ari Berman. Farrar, Straus and Giroux. 358 pages. $27.

The Fifteenth Amendment to the U.S. Constitution, which was ratified in 1870, declares that “the right of citizens of the United States to vote shall not be denied or abridged . . . on account of race, color, or previous condition of servitude.” It also stipulates that “Congress shall have power to enforce this article by appropriate legislation.” For a century after the collapse of Reconstruction, officials sworn to uphold the Constitution used obstruction, evasion, intimidation, and fraud to negate the amendment…