How many African Americans became United States senators and representatives by 1900?

After Congress and the federal government effectively lost interest in Reconstruction the Southern states enacted what were known as the Jim Crow laws. This was legislation that systematically excluded African Americans from the political process, both as voters and as elected representatives. Inevitably, the Jim Crow laws had a disastrous effect upon the number of African Americans in the US Congress. In December 1887, for the first time in decades, Congress convened without a single African American representative. Although three black men served in the 51st Congress from 1889–91, the long-term political representation of African Americans substantially declined as the national focus on civil rights issues faded.
In the decade 1891–1901 only five African Americans were elected to the House of Representatives: Henry Cheatham; George White; Thomas Miller; George Murray; and John M. Langston.