Mahalia Jackson in the context of "March on Washington"

The March on Washington for Jobs and education (commonly known as the March on Washington or the Great March on Washington) was held in Washington, D.C., on August 28, 1963. The purpose of the march was to advocate for the civil and economic rights of African Americans. At the march, several popular singers of the time, including Mahalia Jackson and Marian Anderson, performed and many of the movement's leaders gave speeches. The most notable speech came from the final speaker, Martin Luther King Jr., standing in front of the Lincoln Memorial, as he delivered his historic "I Have a Dream" speech in which he called for an end to legalized racism and racial segregation.

The march was organized by Bayard Rustin and A. Philip Randolph, who built an alliance of civil rights, labor, and religious organizations that came together under the banner of "jobs and freedom." Estimates of the number of participants varied from 200,000 to 300,000, but the most widely cited estimate is 250,000 people. Observers estimated that 75–80% of the marchers were black. The march was one of the largest political rallies for human rights in United States history. Walter Reuther, president of the United Auto Workers, was the most integral and highest-ranking white organizer of the march.

"I Have a Dream" is a public speech that was delivered by American civil rights activist and Baptist minister Martin Luther King Jr. during the March on Washington for Jobs and Freedom on August 28, 1963. In the speech, King called for civil and economic rights and an end to legalized racism in the United States. Delivered to over 250,000 civil rights supporters from the steps of the Lincoln Memorial in Washington, D.C., the speech was one of the most famous moments of the civil rights movement and among the most iconic speeches in American history.

Beginning with a reference to the Emancipation Proclamation, which declared millions of slaves free in 1863, King said: "one hundred years later, the Negro still is not free". Toward the end of the speech, King departed from his prepared text for an improvised peroration on the theme "I have a dream". In the church spirit, Mahalia Jackson lent her support from her seat behind him, shouting, "Tell 'em about the dream, Martin!" just before he began his most famous segment of the speech. Taylor Branch writes that King later said he grasped at the "first run of oratory" that came to him, not knowing if Jackson's words ever reached him. Jon Meacham writes that, "With a single phrase, King joined Jefferson and Lincoln in the ranks of men who've shaped modern America". The speech was ranked the top American speech of the 20th century in a 1999 poll of scholars of public address. The speech was described by journalist Sean O'Grady in The Independent as having "a strong claim to be the greatest in the English language of all time".