What is the significance of Hiram Rhodes Revels being elected to the Senate?

Revels arrived in Washington at the end of January 1870, but could not present his credentials until Mississippi was readmitted to the United States on February 23. Senate Republicans sought to swear in Revels immediately afterwards, but Senate Democrats were determined to block the effort. Led by Senator Garrett Davis of Kentucky and Senator Willard Saulsbury of Delaware, the Democrats claimed Revels’s election was null and void, arguing that Mississippi was under military rule and lacked a civil government to confirm his election. Others claimed Revels was not a U. S. citizen until the passage of the 14th Amendment in 1868 and was therefore ineligible to become a U. S. Senator. Senate Republicans rallied to his defense. Though Revels would not fill Davis’s seat, the symbolism of a black man’s admission to the Senate after the departure of the former President of the Confederacy was not lost on Radical Republicans. Nevada Senator James Nye underlined the significance of this event: "[Jefferson Davis] went out to establish a government whose cornerstone should be the oppression and perpetual enslavement of a race because their skin differed in color from his," Nye declared. "Sir, what a magnificent spectacle of retributive justice is witnessed here today! In the place of that proud, defiant man, who marched out to trample under foot the Constitution and the laws of the country he had sworn to support, comes back one of that humble race whom he would have enslaved forever to take and occupy his seat upon this floor."14 On the afternoon of February 25, the Senate voted 48 to 8 to seat Revels, who subsequently received assignments to the Committee on Education and Labor and the Committee on the District of Columbia.