Moreaux's subject is the old Solar do Unhão, an 18th-century group of colonial buildings which were originally a transit place for slaves during the early years of the trade. The buildings subsequently housed a sugar mill (presumably as here depicted by Moreaux) and a tobacco factory. The buildings survive today and house a cultural complex which includes the Museu de Arte Moderna da Bahia.
Moreaux, a pupil of Baron Gros, travelled to Brazil with his brother (and fellow artist) Louis Auguste (known as Moreau) in 1838. The present picture presumably dates to his first years in Brazil when he resided in Recife, prior to moving down to Rio de Janeiro (where he would settle for the rest of his life) in 1841.
For a selection of his Brazilian work, see G. Ferrez, Iconografia do Rio de Janeiro, Rio de Janeiro, 2000, I, pp.557-59, nos 3535-3548.