 Thinly populated , far from the colonial capital of Rio de Janeiro ( which exercised little actual control ) , Rio Grande do Sul was often the target of invasions from its neighboring Hispanic @-@ American colony , the United Provinces of the Río de la Plata ( later Argentina ) . Because the captaincy had to be self @-@ sufficient , the inhabitants of Rio Grande do Sul led lives as merchants , farmers or ranchers , while often also serving as soldiers or militiamen . Owners of large landholdings such as Marques de Sousa 's father and grandfather provided food , equipment and protection for themselves and for families living in areas under their control . Their private defense forces consisted primarily of laborers who were drafted as soldiers . Marques de Sousa grew up in that hostile environment , and from a very young age he listened to war stories recounting the exploits of his relatives against Hispanic @-@ American invaders . 
