Huge needed ! : 1. from whom did the u. s get the california territory? 2. why did america want the california territory? 3. what did america get out of it?

All I know is that the answer to number 1 is Mexico sorry

Q1. The US got the territory from Mexico after the Mexican-American war. This territory made up the south western United States also known as the Alta California territory. We got the territory after a treaty was signed that ended the war.
Q2. American wanted California because at the time a lot of gold was found in this territory. This was one of the leading causes of the gold rush.
Q3. The US gained slave states throughout the south. There was more political power in America. We also gained states like Texas, California , Utah and more.

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.