There are many things to focus on in this picture of Dr Martin Luther King Jr’s joyous homecoming, having received the Nobel peace prize, but your eye can’t help but be drawn to the hands that grasp his. King’s was the voice of the US civil rights movement but human touch was seminal to his message; solidarity was about linked arms, shoulder-to-shoulder physicality. The determination of the women who crowd the car to clutch at his outstretched fingers speaks not of star-struck celebrity but of a desire to share strength and to receive it.

This photograph, taken in Baltimore in 1964, was the centrepiece of Leonard Freed’s book Black in White America, itself a fundamental document of those years, now republished to mark another pivotal juncture in the struggle for racial justice. Freed travelled his segregated country for two years between 1963 and 1965, looking hard at the division that defined it. Some of those pictures – of a corridor of black hands reaching through prison bars, of mass rallies demanding an end to police brutality – could have been taken this summer.

There was optimism to set against that anger, though, and much of it was concentrated in King’s presence. Those twin forces were never better embodied than in this picture. The women’s expressions of excited comradeship are set against the anxiety in the postures of King’s fellow passengers in the car; given the events of the previous 12 months, an open-top motorcade in 1964 was itself an act of courage. King projects none of that anxiety. He was 35, the youngest ever recipient of the peace prize. His speech in Oslo had been full of hope that rings down the decades to our present moment: “I accept this award today with an abiding faith in America and an audacious faith in the future of mankind. I refuse to accept despair as the final response to the ambiguities of history.”

Black in White America, 1963-1965 is out on 17 November (Reel Art Press)