In the United States, black genocide is a historiographical framework and rhetorical term used to analyze the past and present impact of systemic racism on African Americans by both the United States government and white Americans. The decades of lynchings and long-term racial discrimination were first formally described as genocide by a now-defunct organization, the Civil Rights Congress, in a petition which it submitted to the United Nations in 1951. In the 1960s, Malcolm X accused the US government of engaging in human rights abuses, including genocide, against black people, citing long-term injustice, cruelty, and violence against blacks by whites.

The black genocide analogy has historically been applied to the war on drugs, war on crime, and war on poverty for their detrimental effects on the black community. During the Vietnam War, the increasing use of black soldiers was criticized as an expression of black genocide. In recent decades, the disproportionately high black prison population has also been described as black genocide.

Critics of the black genocide framework describe it as a conspiracy theory, while its proponents argue it is a useful framework for analyzing systemic racism. Arguments against birth control, in particular, have been criticized as conspiratorial or exaggerated, although attempts at black population control and government-sponsored compulsory sterilization did occur as recently as the 20th century.

Slavery in general and the Atlantic slave trade in particular was an archetypal example of a crime against humanity in the 19th century, a larger category of crimes that was expanded when genocide was included in it in the 20th century. George Washington Williams popularized the concept of crimes against humanity with regard to the history of slavery in the United States and during the Congo Free State propaganda war of the 1890s, the "laws of humanity" were included in the Martens Clause of the Hague Conventions and as a result, they were legally enshrined in international law.

Canadian scholar Adam Jones characterizes the mass death of millions of Africans during the Atlantic slave trade as a genocide, calling it "one of the worst holocausts in human history" due to the fact that it resulted in 15 to 20 million deaths according to one estimate, and he has also stated that arguments to the contrary, such as the argument that "it was in slave owners' interest to keep slaves alive, not exterminate them", is "mostly sophistry" since "the killing and destruction were intentional, whatever the incentives to preserve survivors of the Atlantic passage for labor exploitation. To revisit the issue of intent already touched on: If an institution is deliberately maintained and expanded by discernible agents, though all are aware of the hecatombs of casualties it is inflicting on a definable human group, then why should this not qualify as genocide?"

In his book, The Broken Heart of America, Harvard professor Walter Johnson wrote that on many occasions throughout the history of the enslavement of Africans in the US, many instances of genocide occurred, instances which included the separation of men from their wives, effectively reducing the size of the African-American population. For a black American who lived during the era of U.S. slavery, no rights were guaranteed, whether they were personally enslaved or not. In the United States a slave's life expectancy was 21 to 22 years, and a black child through the age of 1 to 14 had twice the risk of dying of a white child of the same age.

The United Nations (UN) was formed in 1945. The UN debated and adopted a Genocide Convention in late 1948, holding that genocide was the "intent to destroy, in whole or in part", a racial group. Based on the "in part" definition, the Civil Rights Congress (CRC), a group composed of African Americans with Communist affiliations, presented to the UN in 1951 a petition called "We Charge Genocide." The petition listed 10,000 unjust deaths of African Americans in the nine decades since the American Civil War. It described lynching, mistreatment, murder and oppression by whites against blacks, concluding that the US government was refusing to address "the persistent, widespread, institutionalized commission of the crime of genocide". The petition was presented to the UN convention in Paris by CRC leader William L. Patterson, and in New York City by the singer and actor Paul Robeson who was a civil rights activist and a Communist member of CRC.

The Cold War raised American concerns about Communist expansionism. The CRC petition was viewed by the US government as being against America's best interests with regard to fighting Communism. The petition was ignored by the UN; many of the charter countries looked to the US for guidance and were not willing to arm the enemies of the US with more propaganda about its failures in domestic racial policy. American responses to the petition were various: Radio journalist Drew Pearson spoke out against the supposed "Communist propaganda" before it was presented to the UN.