From the introductory page of The Trees of Princeton University:

The Princeton University campus might be viewed as a vast arboretum—a carefully planned garden that, with its mix of exotic imports and native species, would never be duplicated in nature.

The verdant place we know today did not exist throughout Princeton’s history. Until 1776 the “college yard,” as the campus was called, had changed little from the cleared land donated by Nathaniel FitzRandolph more than a decade earlier. Those who passed along the King’s Highway (later called Nassau Street), looked across a bare lot at the imposing form of Nassau Hall, one of the largest stone buildings in the Colonies, and perhaps noted with pleasure the simple elegance of the President’s House (now Maclean House). Still, Nassau Hall and the President’s House sat upon a treeless hill.

Matters eventually improved, beginning with the planting of the so-called “Stamp Act sycamores.”

Here is the complete text of The Trees of Princeton University