Were African Americans in attendance to witness the legislative debates that shaped their freedom? Well, yes and no. The nation barred them from citizenship and service as Members of Congress until the adoption of the 14th Amendment in 1868, but barring African Americans, slave or free, from the Capitol has a murkier history.
The House wing of the Capitol was completed in 1803, and almost immediately the visitors' galleries became a contested space. Initially, black visitors, both enslaved and free, attended sessions of the House, observing from the gallery. In November 1804, the House took up a motion that "blacks and people of color, other than freemen, shall be excluded from the gallery." Only one Member voted for the measure.
African Americans continued to watch House sessions from the galleries for the next two decades. However, in 1829, Congress directed the District of Columbia to bar all African Americans from the entire Capitol complex unless they had specific business in the building. This practice continued, likely with varying degrees of enforcement, for decades.
At some point before the end of the Civil War, black visitors again gained regular admittance to the galleries of the House. Newspaper reports from as early as 1864 describe black and white visitors sitting together in the House galleries. By the time the 13th Amendment passed the House in 1865, desegregated galleries had been a common sight in the House for almost a year. As Reconstruction ended in the 1870s, the House galleries were informally segregated by both gender and race, a practice that continued into the 20th century.
And what about access to the Capitol beyond the visitors' galleries? The Reconstruction period was a watershed moment for African-American access to the House Floor, even before 15 black men won election to represent southern states under Reconstruction governments between 1870 and 1887. In 1865 many black visitors filled the House Chamber (while the House was not in session) to hear an address by local minister Henry Highland Garnet commemorating the House's passage of the 13th Amendment. John Willis Menard was the first African American to address the House while it was in session, when he unsuccessfully defended his right to a contested Louisiana House seat in early 1869. The House admitted Frederick Douglass to the House Press Gallery in the 1870s as the editor of Washington's African-American newspaper, the New National Era. His departure, however, marked the absence of black reporters in the gallery until the mid-20th century. According to one 1930s journalist observer, an African-American reporter representing "a large Negro publication," submitted his credentials and proved his mettle by filing "a large quantity of telegraphic copy to his paper every day." The journalist concluded that "it was to no avail. His claim was legitimate, but his color was wrong." African-American Members of Congress in the 20th century drew attention to segregation in other areas throughout the Capitol, most notably challenging segregation in the House Restaurant.
Sources: Annals of Congress, November 8, 1804; Hampshire Gazette, "Intelligencer," 22 January, 1806; Margaret Bayard Smith, A Winter in Washington, Volume I (New York: E. Bliss and E. White, 1824); Ordinances of the Corporation of Washington, Chapter LXXII, in Worthington G. Snethen, The Black Code of the District of Columbia in Force September 1st, 1848 (New York: The A. & F. Anti-slavery Society, 1848); Constance McLaughlin Green, The Secret City: A History of Race Relations in the Nation's Capital (Princeton: Princeton University Press, 1967); Cleveland Plain Dealer, April 13, 1864; Donald A. Ritchie, Press Gallery: Congress and the Washington Correspondents (Harvard University Press, 1991); Washington Merry Go-Round (New York: Blue Ribbon Books, 1931).