[2] The Blackburns were jailed but were allowed visitors, which provided the opportunity for Lucie to exchange her clothes and her incarceration with Mrs. George French.
[4] Lucie was then smuggled across the Detroit River to safety in Amherstburg, in Essex County, Upper Canada.
The day before Thornton was to be returned to Kentucky, Detroit's black community rose up in protest in the Blackburn Riots.
During the commotion, two individuals called Sleepy Polly and Daddy Walker helped Thornton escape and eventually find safety in Essex County, Upper Canada.
[2] Once in Essex County, Thornton was jailed briefly while a formal request for his return was issued by the Michigan territorial governor.
A reply came from the Lieutenant-Governor of Upper Canada, Major General Sir John Colborne, who refused extradition to the United States, noting that a person could not steal himself[6] and that lifetime slavery was too severe a punishment for any crime less than murder.
[2] In 1834, Thornton reunited with his wife Lucie in the newly incorporated City of Toronto, where he worked as a waiter at Osgoode Hall.
Thornton participated in the North American Convention of Colored Freemen at St. Lawrence Hall in September 1851, was an associate of anti-slavery leader George Brown, and helped former slaves settle at Toronto and Buxton.
[11] In 2016, a conference centre at George Brown College in Toronto was named for Thornton and Lucie Blackburn, and a mural depicting their story has been painted in the building's downstairs lobby.