With the independence of Brazil, the emperor Pedro I began the formation of a navy, hiring the services of Lord Thomas Cochrane, having sent Felisberto Caldeira Brant to Great Britain to recruit officers, among them James Norton.

[3] Soon after he assumed and commanded the naval division blockading Buenos Aires, achieving several victories and distinguishing himself in many battles, particularly those of 30 July 1826, 8 April and 7 December 1827 and of 16 June 1828.

[8] He successfully led the blockade of the Río de la Plata, which brought Argentine public finances to the brink of collapse, hastening the peace agreement that ended the war, despite Brazilian defeats on land.

Norton then destroyed the best ships of the Argentine fleet: the frigate 25 de Mayo, the brigs Independencia, Republica, Congreso and General Brandzen.

The couple's enthusiasm for the new country, according to British historian Brian Vale, is revealed by some of the names given to their children: Fletcher Carioca, Fredrick da Prata and Maria Brasília.