This summer, Iwan Russell-Jones travelled to Memphis, Tennessee, with his friend and former colleague Will Coleman, to make a documentary feature for BBC Radio. Will is a professor of theology in Atlanta, and has researched into the experience of the African American slaves. His journey to Memphis was a return to his roots.

We walk on past the statue of Elvis and all the shops stacked with his nicknacks. The King doesn't detain us.

Beneath a banner heavy with texts, a preacher is doing unequal battle with the decibels, yelling about the blood of Jesus above the flattened thirds and sevenths. No one takes any notice. They're more interested in a group of teenage boys who are performing somersaults down the centre of the road.

A flabby, middle-aged man throws some coins in their tin, and clutching what is clearly the latest in a long line of beers, feels it necessary to explain to us that he doesn't want these guys stealing his girlfriend. Why such superbly built kids would be in the slightest bit interested in his equally flabby, middle-aged date is a mystery to me.

But, as Will points out, our drunk is white, the gymnasts are not, and this is Memphis. Race still matters in the land of the free and the home of the brave. Especially after a few beers.

Alice Coleman – everyone calls her AC – is Will's 90 year-old grandmother, and this is the first time I've met her. But she's attained an almost mythic status in my mind. I've heard Will speak of her many times, and he often quotes her in learned articles and lectures. She's his teacher, his inspiration, and sometimes, too, I think, his bad conscience.

AC is a living link with the focus of Will's academic work – the slaves. He's been studying a large body of interviews and testimonies called The Slave Narratives, and is especially interested in their religious language and experiences which have so powerfully shaped African-American identity. Alongside all the literary sources is a living text – his grandmother.

Ever since Will can remember, AC has told him stories about her own grandfather, Caleb Spann, who was a slave in South Carolina. She told him about Caleb's reputation as a root doctor, his involvement in illicit prayer meetings on the plantation, and some of his religious practices with their unmistakeable echoes of Africa.

She told him other stories, too, about slave life in general, the barbarity of separating children from their parents, and about Momah Hannah, the woman who raised her.

She was just a little girl and she could hear Momah Hannah inside the house, rocking backwards and forwards and clapping her hands saying that 'her feet had been taken out if the miry clay and placed on the rock of eternal life. No one could ever take her from that shore.'

Will asks AC if she ever regrets having come through 'ligion herself. 'Regret it? Why would I ever do that? Knowing God and Jesus Christ? No sir... That was the best gift I ever had. But you know, 'ligion is easier to get than to keep. If you want to go to heaven, you gotta act like you're going there – you gotta keep God's commands.'

AC's life spans the century, and many hard and bitter moments in African-American experience.

As she recalls the years of the Civil Rights Movement, Will discovers for the first time that in April 1968, AC was in Mason Temple to hear Dr Martin Luther King give what turned out to be his very last speech – the famous 'mountain-top' address in which he seemed to foresee his own imminent death.

'It was terrible that somebody should want to kill him. Her was for our race. He was for all the races. He said that one day, white and black would walk hand in hand. It ain't happened yet.'

Books have been written about the gulf in the African-American community between the pacifism of Martin Luther King and the more militant stance of people like Malcolm X. But AC instinctively seems to embody and move between both approaches to political change.

I ask her why it's important to keep all these memories and stories alive, and AC becomes really animated. It's as if she has a special message for me, and through me, to the drunk in Beale Street and to every person busy being white throughout the whole wide world.

'It really is important,' she says, 'cos, see, there ain't gonna be no more slavery. Some people look like they want to bring it back, but it ain't gonna happen. People who never did nothing before will go and get a stick or a gun. There'll be a war first. But, see, there ain't gonna be no more buying and selling of people. Maybe some more killing, but no more slavery...'

© Ship of Fools 1998