The term “capitalism” was almost unknown in the English world until first popularised by English translations of Das Kapital in 1867. This was the work of the father of communism, Karl Marx. The title was translated into English variously as The Capital or simply, Capital.
It was a derogatory term that the free market embraced.
The “free market” of the feudal years briefly discussed by the article wasn’t free as the peasants lived under the heavy hand of royalty.
You have hit the nail on the head but there is one more step.
The economist Hernando De Sota in “The Mystery of Capital: Why Capitalism Triumphs in the West and Fails Everywhere Else” does the most excellent job of explaining why “free trade” alone is not the sufficient answer to the question, what is capitalism.
Westernized understanding for property rights and property transfer play the integral part in transporting trade into capital that can be used by individuals.
Everyone, please see this excellent essay or read De Soto’s book.