A public conversation is needed before a decision is taken on honouring controversial figures from the past such as a Coleraine-born "unsung hero" of the American Revolution Hercules Mulligan, an academic has said.
Dr Adrian Grant, a historical researcher at Ulster University, said people should be judged in the context of their time but added that research is needed before deciding whether commemorating them is necessary.
It follows a row over a move by Causeway Coast and Glens council to honour Mulligan, credited with twice saving George Washington's life.
Councillors could be asked to overturn a recent motion to celebrate Mulligan through a heritage trail in the area, where he lived as a child before his family emigrated to America in 1746.
He went on to spy on the British during the American War of Independence.
But it has emerged that Mulligan, who was born in Coleraine, owned a slave five years after helping to set up an anti-slavery organisation, the New York Manumission Society, in 1785.
Dr Grant said the discussion around the legacy of slavery has come more prevalent following anti-racism protests over the last year.
"All of the personalities that we look at from the past have to be judged in the context of their times, not ours," he said.
"But that requires further study of not just the person and their actions but in the wider context of the time in which they lived.
"It's not just a matter of looking at what was happening at a cursory level, it's more about getting into the detail."
In the case of Mulligan, it would be easy to say he shouldn't be judged by 21st century values, he said.
"But if you dig deeper into the time period he was alive, abolitionism wasn't some kind of a fringe movement, he was abolitionist himself, so there was a recognition that slavery was wrong," he said.
He added: "If you look at the context of the times, we can see that there's complexity, we can see it's not as simple as saying we shouldn't commemorate or we should commemorate based on the values and morals of the 21st century."
It is still possible to commemorate figures from the past, said Dr Grant.
But he added: "If you're going to publicly commemorate someone that's possibly controversial by our standards today, there has to be a public conversation that goes along the commemoration side to ensure that history is fully considered and that there can be education arising from it," he said.
It is an issue that is understood in Northern Ireland where figures or events from the past sometimes can't be openly commemorated in a public space because they are too politically sensitive, he said.
Dr Grant added: "There are some things that shouldn't be commemorated in my opinion because they are unsavoury characters or to do with the place that they are being commemorated.
"In my mind, the solution is for there to be a deep consideration of the value of the commemoration in the first place and secondly for there to be an investigation of whether there's an educational value in having the conversation."