[inquest]

Marshall's ruling said nothing about the nature of the market. He was merely defining the activity being regulated. The activity, according to him, involved buying, selling, and transporting goods between states. These are all incidents to a transaction.

Basically, interstate (and foreign) commerce is any commerce which, for a particular state, would be properly described as foreign commerce if that state were an independent country.

[spunkets]

"The activity, according to him, involved buying, selling, and transporting goods between states."

With the inclusion of services and manufacturing, that comprises the market.

"Basically, interstate (and foreign) commerce is any commerce which, for a particular state, would be properly described as foreign commerce if that state were an independent country."

No, it is defined by the scope of the market.