Yes
1956
In California's state constitution they wanted to be admitted into the union as a free state because miner during the gold rush didn't want to have to compete with slave labor. Southern slave owners didn't want that because it would offset the 15 free states and 15 slaves state balance in the senate. If another free state was added the south would lose power. The south feared if they lost power northerners would abolish slavery.
Yes
A new state becomes part of a state when the state they want to join has to accept them if they want to
depending on how you want to view it California was more or less a neautral state though it was classifed as a Union state.
if you want to awnser, us means California
Just about anything they like or want.
no
Well this question makes no sence because California is on the west coast... But if you want to get technical then I guess Florida is the closest east coast state to California if you measure state border to state border.
Yes. South Australia voted in favour of federation.
California.
a state