Bullshit!
Ignorant Yanks always try and lay claim to stuff they know fuck all about.
Meet the Scott Blakey aka master breeder "Shantibaba", creator of the 'White' family of cannabis strains and founder of Greenhouse Seeds.
He's Australian by the way and as far as I know has never lived a day in the USA in his life.
The Cali hippies that moved up into the mountains to escape Vietnam conscription were growing nothing more than south american landrace strains until they got stable hybrid seeds.
This wasn't until David Watson (Skunk_Man) released Skunk #1 under Cultivators Choice in the back of High Times many years after he emigrated from the USA to The Netherlands.
So to clear things up commercial strains came from original work by an American immigrant living in the netherlands that was then developed further (with his own work) by an Australian immigrant living in the netherlands who finally took the mother plants to Switzerland.
The only connection the USA has with the history of commercial cannabis outside of the USA is that David Watson was born there, nothing more.
And the only benefit California has is that it sits at a similar position to Afghanistan and the Hindu Kush mountain range (the geographical home of cannabis) making ideal outdoor growing conditions.
Ideal outdoor is still bunk compared to mid indoor.