Common carrier

Baldwin built the biggest by virtue of its rapport with the U.S. Steel roads. The largest of these properties is the Duluth, Missabe & Iron Range. The Missabe is, to be sure, no granger; indeed DM&IR is only technically a common carrier.

Equally to be expected, in view of the trend of Government legislation and pronouncements over the past few years—but no less epoch-making for that—is the proposal that the railways and canals shall cease to be common carriers and be entirely free to fix their own passenger and freight charges, [...].

The railways were 'common carriers' - they had to move any load they were offered, even if it was uneconomic to do so. Road hauliers could pick and choose their loads.