On this day in 1963, the Reverend Dr Martin Luther King Jr delivered a speech from the steps of the Lincoln Memorial, Washington DC, which remains a defining moment of the US civil rights movement and one of the most iconic orations of the century.

As recalled in the video above, around a quarter of a million protesters had gathered on the National Mall at the end of the ‘March on Washington for Jobs and Freedom’ to hear Dr King give the speech which would become known by the refrain he used in its closing stages, "I have a dream”.

Dr King, who was an energetic campaigner for an end to racial discrimination through non-violent means, said:  "I have a dream that my four little children will one day live in a nation where they will not be judged by the colour of their skin but by the content of their character.”

He said that the fight for racial equality would continue until "justice rolls down like waters and righteousness like a mighty stream".

Remarkably, he had written the speech less than 12 hours before it was due to be delivered, and its famous four word refrain had not initially been part of its text.

“I started out reading the speech, and I read it down to a point … all of a sudden this thing came to me that I’d used many times before - ‘I have a dream’,” Dr King would later recall. “And I just felt that I wanted to use it here … at that point I just turned aside from the manuscript altogether."

The speech drew rapturous applause from the majority of the huge crowd; the New York Times called it “eloquent and moving” and said its delivery was “the high point and climax of the day”, while the Washington Post said the speech “rose above mere oratory”.

Within a year of the speech, the civil rights movement would celebrate the signing of the Civil Rights Act 1964 by President Lyndon Johnson, which prohibited racial discrimination in employment and education and outlawed racial segregation in public facilities.