His younger brother, Guillermo Rawson (1821 - 1890) was also a physician and politician who served as Interior Minister under President Bartolomé Mitre.

[1][4][3] Later, Rawson was part of the San Juan plastic movement promoted by the Philharmonic Dramatic Society, which had been created by Sarmiento.

When he turned eighteen years old, his father sent him to Buenos Aires, where he was a pupil of Fernando García del Molino, under whom he perfected portrait and miniature painting.

However, due to the political conflicts that erupted in the province and his friendship with Sarmiento he was forced to leave the country in 1842, taking refuge in Chile.

He replied as follows:[2] Of course, if you come to America from Europe and for many years have lived in an environment of great artists and great models, finding that these works exist is fascinating, but seeing such flawless execution in unexpected, and the carefully cultivated art, the correct study of drawing, nature perfectly understood, and the choice of color reveal a true painter.

[4] Rawson died in Buenos Aires on 14 March 1871, one of the victims of an epidemic of yellow fever that struck the city in those years.

Rescue in the Cordillera (1855) is a well-known work where his friend Sarmiento and McDonald appears in a heroic episode in which he was not actually involved, in distributing aid from Chile to the survivors of the Unitarian forces that were defeated at the Battle of Rodeo del Medio, surprised by a snowstorm.