Already they had begun to fear, not only for Louisiana and Florida, but even for sultry Mexico and far-away golden California.

It was hard, wrote one of the ablest of the Spanish Governors, to gather forces enough to ward off attacks from adventurers so hardy that they could go two hundred leagues at a stretch, or live six months in the wilderness, needing to carry nothing save some corn-meal, and trusting for everything solely to their own long rifles.
Spaniards Invite Americans to Become Colonists.
Next to secretly rousing the Indians, the Spaniards placed most reliance on intriguing with the Westerners, in the effort to sunder them from the seaboard Americans.

They also at times thought to bar the American advance by allowing the frontiersmen to come into their territory and settle on condition of becoming Spanish subjects.

They hoped to make of these favored settlers a barrier against the rest of their kinsfolk.

It was a foolish hope.