|Landscape with Rainbow, Robert S. Duncanson, 1859|
Born in 1821 in New York, Robert S. Duncanson was a descendant of freed slaves who practiced in Hudson River School and helped develop the Ohio River Valley landscape tradition. He is said to be the equal of fellow Hudson River artists Thomas Cole, Asher Brown Durand, and John Frederick Kensett.
Duncanson had no formal art education, which I suspect is an artifact of his times. He began his career as an itinerant portraitist, eventually moving into landscape painting, which was in en vogue during much of his lifetime.
He was patronized by abolitionists, who financed his works and also commissioned some with abolitionist messages. At the beginning of the Ware Between the States, he moved outside the US, eventually settling in Canada. He was enthusiastically accepted in that country. Later, he moved to Great Britain for a time, and returned to the US in 1867.
Later in his career Duncanson developed dementia, perhaps from lead poisoning or schizophrenia. He continued working, but suffered a seizure while setting up an exhibition in 1872, dying later that year at the age of 51.