In the latter half of the 1920s, a half dozen North American, British, and Canadian engineers and geologists individually began secretive explorations for oil, minerals, and likely locations for rubber plantations in the Brazilian Amazon jungle. Their goal: to interest the Ford, Firestone, and Goodyear companies in land that would supply the raw materials for their product—tires. As these land speculators negotiated with the Amazonian state governments for concessions, each thought he had claimed the richest territory with virtually unlimited exploitation privileges. Several scrambled for concessions, and by July of 1927 one individual obtained 2.5 million acres on the Tapajós river in the Amazonian state of Pará. He secretively planted half a million rubber seedlings in the forest (an indication of the vastness, sparse population, and poor communications in the Amazon at that date) and left behind an armed guard to protect the land against incursions by other speculators (Winter, 1927). In a subsequent contract with Pará, Henry Ford then acquired this land to grow rubber.