According to https://en.wikipedia.org/wiki/Capitalism#Etymology, the word capitalism was in use starting in the 1700s. I'm curious what the founding fathers thought of Adam Smith and capitalism. If they didn't consider the US a capitalist country, then where did the idea that the US is a capitalist country come from?
As the etymology in the link you provided also points out, the 18th century understanding of the word capitalism derived from "capitalist", a person living off of the interest of his capital. Basically the literal description of the idle rich.
It was not used as the term for an economic system until the mid 19th century. As such none of the founding fathers would have thought of the US as a capitalist country.