Passing, in the context of race, occurs when one conceals their socially applied racial identity or ethnicity in order to be perceived as another race for acceptance and/or other benefits. Historically, the term has been used primarily in the United States to describe a person of mixed race who has assimilated into the white majority to escape the legal and social consequences of racial segregation and discrimination. In the Antebellum South, passing as White was sometimes a temporary disguise used as a means of escaping slavery, which had become a racial caste.

Although anti-miscegenation laws outlawing racial intermarriage existed in the North American Colonies as early as 1664, there were no laws preventing or prosecuting the rape of enslaved girls and women. Rape of slaves was legal and encouraged during slavery to increase the slave population. As a result, for generations, enslaved women (who might also be mixed-race) bore mixed-race children who were deemed "mulattos", "quadroons", "octoroons", or "hexadecaroons" based on their percentage of "black blood".

Although these mixed-race people were often half White or more, institutions of hypodescent and the 20th-century one drop rule in some states – particularly in the South – classified them as black and therefore, inferior, particularly after slavery became a racial caste. But there were other mixed-race people who were born in colonial Virginia among the working class to unions or marriages between free white, almost exclusively Irish, women and African or African-American men, free, indentured, or slave, and became ancestors to many free families of color in the early decades of the United States, as documented by Paul Heinegg in his Free African Americans of Virginia, North Carolina, South Carolina, Maryland and Delaware.

For some people, passing as White and using their whiteness to uplift other black people was the best way to undermine the system that relegated black people to a lower position in society. These same people that were able to pass as white were sometimes known for leaving the African American community and getting an education, later to return and assist with racial uplifting. Although the reasons behind the decision to attempt to pass are deeply individual, the history of African Americans passing as white can be categorized by the following time periods: the antebellum era, post-emancipation, Reconstruction through Jim Crow, and present day.

During the antebellum period, passing as white was a means of escaping slavery. Once they left the plantation, escaped slaves who could pass as white found safety in their perceived whiteness. To pass as white was to pass as free. However, once they gained their freedom, most escaped slaves intended to return to blackness—passing as white was a temporary disguise used to gain freedom. Once they had escaped, their racial ambiguity could be a safeguard to their freedom. If an escaped slave was able to pass as white, they were less likely to be caught and returned to their plantation. If they were caught, white-passing slaves such as Jane Morrison could sue for their freedom, using their white appearance as justification for emancipation.

Post-emancipation, passing as white was no longer a means to obtain freedom. As passing shifted from a necessity to an option, it fell out of favor in the black community. Author Charles W. Chestnutt, who was born free in Ohio as a mixed-race African American, explored circumstances for persons of color in the South after emancipation, for instance, for a formerly enslaved woman who marries a white-passing man shortly after the conclusion of Civil War. Some fictional exploration coalesced around the figure of the "tragic mulatta", a woman whose future is compromised by her being mixed race and able to pass for white.^{[citation needed]}

During the Reconstruction era, black people slowly gained some of the constitutional rights of which they were deprived during slavery. Although they would not secure "full" constitutional equality for another century until after passage of the Civil Rights Act of 1964 and Voting Rights Act of 1965, reconstruction promised African Americans legal equality for the first time. Abolishing slavery did not abolish racism. During Reconstruction whites tried to enforce white supremacy, in part through the rise of Ku Klux Klan chapters, rifle clubs and later paramilitary insurgent groups such as the Red Shirts.

Passing was used by some African Americans to evade segregation. Those who were able to pass as white often engaged in tactical passing or passing as white in order to get a job, go to school, or to travel. Outside these situations, "tactical passers" still lived as black people, and for this reason, tactical passing is also referred to as "9 to 5 passing." The writer and literary critic Anatole Broyard saw his father pass in order to get work after his Louisiana Creole family moved north to Brooklyn before World War II.