1863 The reason why black Americans gathered in front of the Lincoln Memorial in August was that,

Protest against the unfair treatment and discrimination of blacks by the American government and army. During the Civil War, African-Americans fought for the Union Army in the North, but after the war, they were not treated and respected as they deserved. On the contrary, they face all kinds of discrimination and injustice, such as restrictions on employment opportunities, deprivation of education rights, deprivation of voting rights and so on. African-Americans were dissatisfied and angry about this and decided to express their demands and protests through rallies. The rally attracted thousands of African-Americans, who held up banners and delivered speeches, calling on the government and the military to respect their rights and dignity.