Why did California's application for statehood upset some people?

Because at the time of it's application there was an equal number of slave and non slave states striking up a delicate balance to keep peace. California was applying as a non slave state which would there fore tip the balance that way which caused a total uproar.

Explanation:

1. it was caused by feudalism

2. charlemagne used christianity as a major cornerstone for his rule. cloisters were built all over the empire to act as centers for the (re)population of the vast european wilderness.

3. the europeans feared the next raid every time chetak

i'm not so sure about #6. but i hope i you with the first 3.