San Diego is still the main US Navy base on the West Coast due to its excellent natural harbor. Tijuana isn't the city it is today since it's growth was largely spurred by its close proximity to San Diego, instead the entire Mexican Gold Coast is simply more suburban sprawl from San Diego proper.
San Diego may possibly be much bigger. Part of the reason that LA grew after the 1906 SanFran earthquake is that the railroad didn't stretch as far as San Diego's excellent harbor so shipping traffic went to LA instead. However, if Baja is a state there's going to be a big push to connect it to the US and build a railroad all the way down the west coast. That means when the 1906 earthquake happens and SanFran's harbor is out of commission San Diego will be the best harbor in California with a rail connection. San Diego then gets the snowballing growth that LA got in our history. LA in this timeline is likely a mid-sized city.
I agree with that, @thekingsguard; will it be divided at the Missouri Compromise line, or as OTL? And, will South California be admitted as a slave state?
This looks likely.Maybe Baja becomes another Florida and you get a ton of retirees moving down there and holidaygoers going there due to the good weather and beaches
I agree with that, @thekingsguard; will it be divided at the Missouri Compromise line, or as OTL? And, will South California be admitted as a slave state?
I agree with that, @thekingsguard; will it be divided at the Missouri Compromise line, or as OTL? And, will South California be admitted as a slave state?
Just to keep in mind in reference to any splitting of a state you need the state to agree to it and California refused an attempt by congress in the 1850's to divide it.