Sisley did not live to see his talent recognized, however, a year after his death, his painting "Flood at Port-Marly" (Orsay Museum - Paris) reached a high bidding.
Sisley was exclusively a landscape painter, who, in the line of Corot, and with Claude Monet, best sought and succeeded in expressing the most subtle nuances of nature in Impressionist landscapes. 
Flood at Port-Marly
The flood of 1876 at Port-Marly, France, became the subject of a large series of his landscapes
He painted 7 canvas on this event.