> Who said anything about Medicaid? That is a Federal program that States can opt into to varying degrees, and most States have longstanding separate programs for the purpose.

No, they don't. Many states name their Medicaid-participating program with a local name that does not include “Medicaid”—California’s is “Medi-Cal”, Oregon’s is “Oregon Health Plan”—but none of them have a general, broad coverage health insurance program for the poor that is not the state Medicaid plan (except to the extent that their CHIP program is separate from their Medicaid program, but that is usually not the case, and CHIP is, in any case, a similar federal program to Medicaid, but newer.)

> I should add, all of my experience is decades before the ACA Medicaid expansion.

At a minimum, your generalization of your experience across the country and across times and to the whole body of the poor and not those in specific circumstances, and the understanding of the administrative context which enabled your experience, is incorrect, but it's quite possible that the reported experience itself rather than the generalizations based on it (that is, that you had decent, free healthcare while being poor in the US) is correct, especially as a child.