The Wealth of Nations by Part 4 Chapter 7 Page 50

But the political institutions of the English colonies have been more favourable to the improvement and cultivation of this land than those of any of the other three nations.

First, the engrossing of uncultivated land, though it has by no means been prevented altogether, has been more restrained in the English colonies than in any other. The colony law which imposes upon every proprietor the obligation of improving and cultivating, within a limited time, a certain proportion of his lands, and which in case of failure, declares those neglected lands grantable to any other person, though it has not, perhaps, been very strictly executed, has, however, had some effect.

Secondly, in Pennsylvania there is no right of primogeniture, and lands, like movables, are divided equally among all the children of the family.