Money can be used to measure value. If I offer you a billion dollars to chop off your arm and eat it raw, then your response to that offer indicates to me how much you value your health. But, if I'm a trillionaire, that billion dollars represents 0.1% of my total wealth, so the marginal cost to me is negligable. The perceived value of a dollar is proportional to the observer's wealth. Are they related? Sure, but it's way more complicated than that.
> Money is just score keeping for value created.
Yes and no. It's way more complicated than that. As demonstrated with the slavery example (nobody accused you of being pro-slavery, please chill), money is often score-keeping for handling money. People with power who participate in large transactions take a cut for themselves. In the case of slavery, the plantation owners got rich by what we consider outright theft today. Money and power follows their descendants, and for what? Did they create value? No, they're just rich off the proceeds of slavery.
Take Mozilla for example: developers are, by and large, the greatest value-creators at the company. So why does Mitchell Baker make $2.5M a year? What great value is she creating? Is she secretly an honest-to-goodness 10x developer? I see no evidence of such -- but because she's closest to the money, she makes decisions about the money, and folks at the board (who are, typically, CEOs at other orgs) agree that people who are closest to the money deserve to get the most money. In this example, the accumulation of wealth is not a record of created value but it's a record of power.
My definition of value is rather irrelevant. There is no universal definition, and I'd say that any precise definition is flawed. Especially one so simple as "value == money".