Early fur trappers in California helped pave the way for later American migrants in several ways:
Charting territory. Fur trappers were among the first people to explore new territory. Initially, this was done to improve and increase the fur trade. However, it also helped establish new settlements and roads in newly discovered territories.
Establishing contact and alliances with indigenous people. As fur trappers were often the first to arrive to lands exclusively inhabited by indigenous people, they were instrumental in creating alliances, partnerships or business contracts with them.
Establishing first settlements. As the fur trade decreased, traders started settling in the areas they had explored, which led to the development of new settlements further west.
Opening trails for immigration. As a product of their exploration, new trails were discovered and improved, in particular for wagon trains. This meant that settlers could more easily expand through the new territories and populate the previously unexplored area.
