Toronto (ENI). Christians in Toronto have commemorated the 200th anniversary of the law abolishing the slave trade in the British Empire, at a service in a church founded as the city's first black congregation in 1826. "If we don't remember, we can't undo the effects of slavery," Pastor Fred Witteveen told an overflow crowd of white and black Christians at the 25 March service. It marked the start of a year-long exploration by churches of the legacy of the slave trade and about racism today. "We must recognise that Canadian society was built on the blacks of slaves and of aboriginal people," said Nora McMurtry, co-chair of the Canadian Ecumenical Anti-Racism Network of the Canadian Cuncil of Churches which sponsored the event. "Church leaders even owned slaves."