In flip-flops, a faded old T-shirt and ragged trousers, Abraham Laeyea looked the image of Africa's frustrating, dispiriting poverty. "We like Obama," he said. "We want him to come and rule all African countries. He brings hope but we need employment, jobs for the youth. Yes, we all have schooling as far as O-level here but then there is no work. People who have succeeded with business in this area move away."

Abraham was among the young men standing in a crowded street beside an open drain in Jamestown, once a flourishing fishing village on the edge of the capital, now one of the city's poorest areas. The seaside slum of shacks is home to thousands of people. Most make ends meet by casual labouring or by buying something – anything, a couple of batteries or a plastic key ring – and selling it for a tiny margin. Most eat once a day, if they are lucky.

These people represent the challenge that President Barack Obama is trying to address with a major policy speech today addressed not just to Ghana, but to Africa. He flew here straight from the G8 summit in Italy where promises were remade to help Africa reach the Millennium Development Goals in health, infant mortality and education. Ghana is one of the few African countries which might reach them.

Download the new Independent Premium app Sharing the full story, not just the headlines

Between 1992 and 2006, the percentage of the population in poverty dropped from 52 per cent to 28 per cent. Politically too, it is stable. After two decades of chaotic and often violent politics it hit rock bottom in 1983, but a decade later democracy was restored and since then five elections have been held, two of them resulting in a change of ruling party.

There is no doubting the goodwill that Ghana has poured out to welcome the American President, even if some Ghanaians are a bit blasé about visiting US leaders. Bill Clinton came in 1998, drawing his largest ever crowd. And last year, George Bush came to Accra on one of his last foreign outings. The streets of the capital are lined with the stars and stripes alongside Ghana's national flag and pictures of Mr Obama and President Atta Mills. The street hawkers have abandoned their usual fare of newspapers, plastic flowers and sunglasses in favour of Barack and Michelle T-shirts. Women walk tall in full-length costumes imprinted with Mr Obama's face.

But few will see America's first black President in the flesh. Security as well as a forecast of heavy rain have forced him to hold his major policy speech in a conference centre before visiting the slave fort at Cape Coast. The main thrust of his policy, already laid out by Johnnie Carson, head of the Africa bureau at the State Department, encourages African governments to rule better and end conflicts then concentrate on growing their economies. He does not put aid to Africa at the top of his priorities but appears to be trying to look beyond to an Africa that earns its living in the world, no longer reliant on aid.

Ghana's government receives 16 per cent of its GDP and 73 per cent of its government expenditure from aid. The US provides part of that but its trade with and investment in Ghana is tiny. Next year Ghana's newly discovered oil comes on stream but no US oil major has shown much interest, and the small company developing it is more likely to sell to China. There is little sign that American companies are flocking to invest in the country.

But Ghana is important to America in another way. It was chosen for Mr Obama's first visit to sub-Saharan Africa because it was the first African country to become independent. Though less important than Nigeria or South Africa, it is seen as a leader in Africa and the destination for many African-Americans and African-Caribbeans returning to their "homeland".

Known as the Gold Coast before independence, Ghana is also littered with remnants of the slave trade of which 10 major sites built by European traders remain, places of painful pilgrimage for black visitors from the Americas. Today, the President and Mrs Obama, who is descended from slaves, will visit Cape Coast fort, a major Swedish, Dutch and lastly British slave trading post. Inside its massive walls, a Latin inscription in stone in the courtyard proclaims faithfulness to God, and its upper rooms are elegant but simple with pleasant views of the sea. Below, in shocking contrast, is a vast dungeon where slaves were crammed in and kept manacled until they were shipped to America.

Yesterday, representatives of the African American diaspora communities held a highly charged meeting in Accra recalling this past and welcoming Mr Obama and his family, though in private they complained that they had yet not been invited to any events. "He gives us the psychic energy we need," said Dr Charlotte Gardener, president of the Caribbean Ghana Association. "We are so happy to see one of our own coming out of America." Questioned about Mr Obama's own ancestry (his father was Kenyan so he does not come from a slave background) Janet Butler, an African American who has lived in Africa for 14 years, said that although he is not "old diaspora", his life choices have made it clear that he is able to identity with their experience.

President Obama has been slow to turn to Africa, expending more energy on the Middle East. But he has kept the US on track to meet its Gleneagles G8 aid commitments made in 2005. He also appears to be looking beyond aid to ways in which African countries can make sustainable improvements to farming production.

All of which will be good news for one of the world's biggest cocoa producers and potentially a huge food producer. That may not provide a job for Abraham and his friends soon but they live in hope. Ghanaian shopkeepers love to give their shops slogans, often religious ones. One in Jamestown reads, "Never give up – there is time for everything".

Do we square up? Mini-Obama eager to see real thing

It is an uncanny resemblance and one that has turned the Ghanaian schoolboy Felix Afriyie into something of a celebrity. "Even in school, my mates, my teachers call me Obama," he said as the west African country whipped itself up into a frenzy ahead of the US President's visit. He has travelled 125 miles from his hometown of Kumasi to be in the capital, Accra, for a chance of seeing his lookalike. His father, Agyaba, a gold jeweller, said: "My son to meet Obama face to face, I would be proud of it." But Felix, it seems, does not want to grow up to be a president. He hopes instead to become a pastor.