I lived in California through the CARB and EPA mess during the 70s, 80s, 90s, etc. (We are unable to dissolve agencies once they have been established. We can only add more of them and increase their size and purview of these bureaucracies.)
Anyway, California kinda started the whole thing with instantiating "smog laws" on cars and trucks. Attacking the biggest contributors to smog first. Fed politician's simply adopted a new "cause" to rally popular support and ride the voter swell of "righteousness" into office, and resulting in the creation of the EPA.
The California version of history is here. Some of it is interesting. Start at the bottom of the timeline.
http://www.arb.ca.gov/html/brochure/history.htmMotorcycles were ignored in the earlier years, but the EPA included them in their 1977 law, which became enforceable for the 1978 models. Honda tried to meet the upcoming standards early and show cooperation with fed agencies. So, many mechanical changes were introduced on earlier model, like crankcase gas scavenging and later, lean burn idle operation for 77.
California did drive earlier "smog control" efforts. Then the big dog Feds came in to show who was the "boss" of the nation, allowing California a "waiver" to enact more restrictive laws.