It was allowed to join the USA as a slave state, on condition that there would be no more slavery North of a line fixed by Missouri's Southern border.
This compromise lasted well enough, until the admission of California made it impractical.
California (as free soil)
California
California became a free state
The State of California became a free State when the Compromise of 1850 was passed.
After the Compromise of 1850 California became a free State, on September 9, 1850.
California is the 31st US State.
California
California
California became a free state
Compromise of 1850
The State of California became a free State when the Compromise of 1850 was passed.
After the Compromise of 1850 California became a free State, on September 9, 1850.
California
Compromise of 1850
california
the most controversial part of the 1850 compromise was California becoming a free state.
The Compromise of 1850
It became the 23rd US State on 15 March 1820.
California