<P> Many popular representations of the movement are centered on the charismatic leadership and philosophy of Martin Luther King Jr., who won the 1964 Nobel Peace Prize for his role in the movement . However, some scholars note that the movement was too diverse to be credited to any one person, organization, or strategy . </P> <P> Before the American Civil War, almost four million blacks were enslaved in the South, only white men of property could vote, and the Naturalization Act of 1790 limited U.S. citizenship to whites only . Following the Civil War, three constitutional amendments were passed, including the 13th Amendment (1865) that ended slavery; the 14th Amendment (1868) that gave African - Americans citizenship, adding their total population of four million to the official population of southern states for Congressional apportionment; and the 15th Amendment (1870) that gave African - American males the right to vote (only males could vote in the U.S. at the time). From 1865 to 1877, the United States underwent a turbulent Reconstruction Era trying to establish free labor and civil rights of freedmen in the South after the end of slavery . Many whites resisted the social changes, leading to insurgent movements such as the Ku Klux Klan, whose members attacked black and white Republicans to maintain white supremacy . In 1871, President Ulysses S. Grant, the U.S. Army, and U.S. Attorney General Amos T. Akerman, initiated a campaign to repress the KKK under the Enforcement Acts . Some states were reluctant to enforce the federal measures of the act; by the early 1870s, other white supremacist and paramilitary groups arose that violently opposed African - American legal equality and suffrage . However, if the states failed to implement the acts, the laws allowed the Federal Government to get involved . Many Republican governors were afraid of sending black militia troops to fight the Klan for fear of war . </P> <P> After the disputed election of 1876 resulted in the end of Reconstruction and federal troops were withdrawn, whites in the South regained political control of the region's state legislatures by the end of the century, after having intimidated and violently attacked blacks before and during elections . </P> <P> From 1890 to 1908, southern states passed new constitutions and laws to disenfranchise African Americans and many poor whites by creating barriers to voter registration; voting rolls were dramatically reduced as blacks and poor whites were forced out of electoral politics . After the landmark court case of Smith v. Allwright progress was made in increasing black political participation in the Rim South and Acadiana--although almost entirely in urban areas and a few rural localities where most blacks worked outside plantations . The status quo ante of excluding African Americans from the political system lasted in the remainder of the South, especially North Louisiana, Mississippi and Alabama, until national civil rights legislation was passed in the mid-1960s to provide federal enforcement of constitutional voting rights . For more than sixty years, blacks in the South were not able to elect anyone to represent their interests in Congress or local government . Since they could not vote, they could not serve on local juries . </P>

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