Garcia was possibly a member of the failed expedition of Juan Díaz de Solís in 1515 and 1516, which sought a sea passage from the Atlantic to the Pacific Ocean.

[2] Melchior Ramírez, in turn, would assist and guide Cristóvão Jacques on his voyage of exploration to the Río de la Plata and the Paraná River in 1521, returning again to Santa Catarina.

Since time immemorial a network of trails called Peabiru criss-crossed this region of South America, linking the lands of the Guaraní to the Inca Empire nearly 1,000 km (620 miles) distant across the semi-arid Gran Chaco.

During his travels, Garcia heard tales of a "white king" who lived to the west, ruling cities of incomparable riches and splendor.

In 1524, Garcia, the mulatto Pacheco, and possibly a few more Spaniards and Portuguese set out from Santa Catarina to journey westward to what would become the site of Asunción, Paraguay, passing Iguazu Falls en route.

After crossing the Gran Chaco, the Guaraní army and the Europeans climbed into the Andes, entering the Inca Empire and reaching Tarabuco, Bolivia.

He sent men, either Guaraní or Portuguese (accounts differ), back to his colleagues who had remained on the Atlantic coast with two or three arrobas, about 40 kg (88 lb), of silver to demonstrate the success of the raid and to request reinforcements.