Why was the early west considered a "crossroads of culture"?

mexico originally owned the land, so the cultures of americans, mexicans, and native americans were all present in the west.

the california gold rush brought in people from all over the world, which resulted in cultural diffusion among the settlers there.

california was known to accept many forms of religion and ethnicities, so people from different cultures migrated there to start new lives.

those settlers who brought slaves with them to the west created cultural interactions between native americans, african americans, and themselves.

The correct answer is "The California Gold Rush brought in people from all over the world, which resulted in cultural diffusion among the settlers there". The California Gold Rush started in 1848 when James W. Marshall found gold at Sutter's Mill, news that attracted 300,000 people to California from around the United States and abroad. This period of the early West is considered a crossroad of culture because people from distant cities and countries interacted with the aim to found gold.

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories