Which group targeted freedmen to promote white supremacy through fear and intimidation?

The Ku Klux Klan is the correct answer because this group was explicitly formed in the aftermath of the Civil War and played a direct role in promoting white supremacy through methods of fear and intimidation. Established in the 1860s, the Klan emerged as a reaction to the Reconstruction era, where freedmen were granted citizenship and rights. Their tactics included violence, threats, and social ostracism to undermine efforts towards racial equality and control the newly freed African American population.

In contrast, the Free Soil Party was primarily focused on preventing the expansion of slavery into the territories; it did not target freedmen in the same way. The Radical Republicans were a political faction dedicated to using the power of the federal government to ensure equal rights for freedmen, often opposing groups like the Ku Klux Klan. The Constitutional Union Party aimed to preserve the Union and did not engage in actions associated with promoting white supremacy or targeting racial groups in a violent manner. This context highlights the distinctive and intimidating role the Ku Klux Klan played in American history regarding the treatment of freedmen during the Reconstruction period.