Yeah, we actually had our own era of “conglomerates” - they were very big from the 1960s through 1980s. Companies like ITT, Cendant, Gulf+Western, GE — formed from tons of acquisitions, sprawling across completely unrelated industries.

At one point in the 1990s, you could buy a toaster from the same company that makes airplane engines, MRI machines, and produces “Saturday Night Live.” And you may have financed that toaster through their financial arm (GE Capital). Eventually the many lines of business were spun off from companies like this.

What came next was a very different type of consolidation - companies like Comcast, Chevron, and the current “AT&T” who went from being regional players to buying as many other companies just like themselves in order to maximize economies of scale - they’re huge but really just do one or two very closely-related things.

I am not an expert, but my impression is that the era of US conglomerates was more a product of the financial superstructure: Post-WW2, demographic, economic, and technological growth created many large opportunities for business ventures. But capital markets were much less sophisticated, much smaller than today.

Existing large businesses were the primary source of major investments in new businesses, or in remaking old businesses for a rapidly modernizing world.