I believe one post above is referring to the Sonnenshein battery which IMO was the finest GEL battery ever made. It was a product of German technology and manufacture. It was made so well it resisted some of the vulnerabilities that plague gel batteries in general.
Every last Optima battery is built in Monterrey, Nuevo Leon, Mexico these days.
Call Johnson Controls, Oxide, and other battery manufacturers and ask them "Are any of your batteries made in Mexico?" I believe East Penn Deka, is the lone holdout because they have their own lead smelter and a virtual lock on the virgin lead in the Eastern USA. Never did ask them if they share lead with Rolls & Surrette. Virgin lead is at a premium these days. The Chinese are eating lead supplies like there's no tomorrow.