1. Who were the “Redeemers” and what did that label mean? What were their goals and objectives?

The "Redeemers" were a group of southern Democrats in league with elite conservative forces in the postbellum southern US. They sought to fight against what they perceived as the imposition of economic and political power on the south during Reconstruction.
Reconstruction brought dramatic changes to the South. In the wake of the Civil War, businessmen (called "carpetbaggers" by the southerners) descended on the South in an attempt to transform the traditional southern economy. Legislation like the Fifteenth Amendment, which gave freed slaves the vote, also changed the political scene.
It didn't take long for southerners to fight back and the "Redeemers" were part of this process. Their political maneuvering saw its greatest success in the Compromise of 1877. This compromise was the end result of the highly contested, problematic presidential election of 1876. As part of a compromise, President, Rutherford B. Hayes, was appointed president by a congressional commission, despite having lost the popular vote. In return for a Republican victory, Democrats insisted that the federal government withdraw occupying troops from certain southern states, effectively ending the Reconstruction period.
What followed in the coming years was disenfranchisement for African-Americans, the introduction of voter restriction via Jim Crow laws, and outright race-based terrorism brought about by organizations like the Ku Klux Klan. The "Redeemers," in league with other southern elites, were largely responsible for orchestrating this backlash.