Aster's problem was exactly the same as the British. He had to find an overland route to the east coast because the journey by ship around the tip of South America was lengthy and very expensive.
The Hudson's Bay Company set up trading forts like Fort Vancouver (now in Washington State) to gather furs, and as a starting out place for the mule trains that took the goods back east.
Astor set up a fort at Astoria. But he needed his own route east that did not go through what was then Canadian territory.
