In 1868, Francis E. Shober was elected as a Democrat to the Forty-first United States Congress from North Carolina’s Sixth Congressional District. However, the election was contested by his Republican opponent, Nathaniel Boyden, who accused Democrats of placing ballot boxes at the polls that were not clearly marked; of intimidating and threatening Republican voters; and circulating a race-baiting forged document –  purporting to come from the chairman of the National Republican Executive Committee – designed to discourage freedmen from voting for Boyden: If we can elect Grant we will not need the negro vote again, and we can assure you our next Congress will inaugurate a system of colonization that will remove the negro from your midst. … By all means, get the negroes to register and enroll, so that we may know their strength.

House and Senate reports are the designated class of publications by which congressional committees formally report and make recommendations to the Senate or House concerning, among other things, their investigative or oversight activities.  These reports are publicly distributed as part of the official U.S. Serial Set record of each Congress. Documents related to Boyden v. Shober appear in the 41st Congressional Serial Set. Among several others, Ransom Miller gave testimony in the matter in Salisbury, North Carolina:

In April 1870, the House of Representatives committee investigating the matter reported that although there was probably some minor intimidation and fraud, there was not enough to change the results of the election. Shober was seated and re-elected in 1870.

Adapted in part from http://ncpedia.org/biography/shober-francis-edwin