After seventeen years as ruler in Argentina, what became of Juan Manuel de Rosas?

After the failed Platine War against the Empire of Brazil, de Rosas, fearing for his life, disguised himself and fled on a boat to the United Kingdom to live in exile, officially ending his reign. He remained in England, struggling with his wealth and never fully recovering to his past glory. One day after he went on a walk on a cold day, he caught pneumonia and subsequently passed away on the 14th of March, 1877.