My people in the Highlands had contact with the outside world for just 50 years at the time while I personally had been in contact with the ‘white man’ for just 17 years. I had first seen a kiap come into my village to conduct a census in 1958.

Sonko shocked me with his disturbing story of slavery in Africa. My people of Enga had fought brutal tribal wars but there was always reconciliation in the end through compensation payments, intermarriage, trade and commerce. We had never owned or sold another human being.

Sonko was from the island of Goree, two miles off Dakar, the capital of Senegal. He told me a Slaves House stands on the island where the ancestors of African Americans were kept in appalling conditions.

Hundreds of thousands of men, women and children from all over Africa were held there and deported to the Americas as slaves starting in the 16th century.

“The Slaves House is actually an ancient fortified warehouse which has walls of stone and one door facing the sea,” Sonko said. “It was owned by white men and guarded by soldiers.”

Goree Island was not the only fort protecting the slave trade, there were many others along the coast of West Africa down to Angola in the south.

The slaves were convicted criminals, prisoners of war, people born into slavery and people who had been kidnapped. At the coastal ports the slaves were exchanged for iron, guns, gunpowder, cloth, gin and other manufactured goods from Europe.

The slaves were branded like cows and locked in the fort to await the next ship to the Americas where they would work on plantations to produce sugar, rum, cotton and tobacco.

Sonko’s story touched my innermost being; I almost wept. I had known that African Americans were descended from slaves but I don’t think I would have known the full story if I hadn’t met him.

“Many blacks cry as soon as they enter the rooms where slaves were chained to the walls,” Sonko said. “Mohammed Ali, Michael Jackson, James Brown, MC Hammer, Bob Marley – they all wept in the Slaves House with its door of no return open to the sea.”

Sonko is from the Mandigo tribe, to which African American author the late Alex Haley traced his slave ancestor, Kunta Kinte, in his best-selling book Roots.

On some weekends while I was in the US, I took solitary walks along the edge of Lake Erie and looked north towards Canada. Many a slave from the Southern states made their escape across this lake to freedom in Canada.

In 1830, one such slave, Josiah Henson, and his mother were later sold separately and the boy almost starved to death from neglect until he was also bought by his mother’s new master. The experience did not break Henson’s spirit.

For many years , not only did he manage the planting, raising and harvesting crops of wheat, oats, barley, potatoes, corn and tobacco but he also took them to market, bargained skilfully and brought home the profits to his master.

Henson decided to escape to Canada and freedom after he had been deceived when trying to buy himself out from slavery.

He was productive and successful in his new life as a free man, establishing a sawmill that shipped walnut timber to Boston, the profits going to found a multiracial school. Henson later made several trips to the South and helped gain freedom for another 118 slaves.

These are big stories.

Not only did early black Americans work on their master’s plantations; they fought in the War of Independence against England. Zechery Prince was killed. Gad Asher was blinded. Slem Poor was commended for bravery. They are among 5,000 ‘forgotten’ slaves and free blacks who fought in the war.

In Washington DC, as I walked down the steps after viewing the famous marble statue of Abraham Lincoln, I looked across the Reflecting Pool towards the Washington Monument.

By 2020, near here, will stand a National Liberty Monument - a memorial to honour those 5,000 of African descent who served as soldiers or sailors or provided civilian assistance during the American Revolutionary War.

At Port Moresby’s Ela Beach, Papua New Guinea has a bronze bust of Raphael Oimbari helping a wounded soldier. It was erected in honour of the ‘Fuzzy Wuzzy Angels who were of such importance to the Allies during World War II.

But perhaps the PNG government should allocate land at a prime location on which to erect a national monument to our founding fathers and the early pioneers who will stand watch over Port Moresby, our capital city.

It would be a national symbol of pride, patriotism and freedom.