That's about what I recall as well.
I'm not sure when the 147 gr. loads became a standard in the subguns. I seem to recall it was either during or shortly after WWII. I may be wrong though.
Seems I recall as well that in the wake of the Miami shootout the FBI initially recommended switching from 115 gr. 9mm loads to the 147 gr. loads hoping for deeper penetration. Many local police Depts., which had just gone to the 9mm from revolvers, followed the FBIs lead and soon had problems with their weapons reliably functioning.
IIRC the problems were caused by a number of factors in a variety of guns. The oal of the cartridges, the weight of the recoil springs which had been carefully calibrated for 115 gr. bullets, unfamiliar recoil, etc. These early problems gave the 147 gr. loads a bad rep for quite some time.
Meanwhile a number of US agencies, the Border Patrol being one. wanted a more powerful loading of the 9mm in a jhp. A +P load. Eventually they got it