Maclure had a highly successful mercantile career, making a fortune that allowed him to retire in 1797 at the early age of 34 to pursue his scientific, geological and other interests.

In 1803 he visited France as one of the commissioners appointed to settle the claims of American citizens on the French government; and during the few years then spent in Europe he applied himself with enthusiasm to the study of geology.

[9] This antedates William Smith's geological map of England and Wales (with part of Scotland) by six years, although it was constructed using a different classification of rocks.

The treatment of Maclure's burial site in Mexico was bereft of the honors due the respected humanitarian and geologist: At the distance of a few feet from them, repose the remains of William McClure, a countryman, dear to American science.

The Academy of Natural Sciences at Philadelphia, of which he was so long the President and benefactor, erected a small marble monument over his grave, and surrounded it with an iron rail.

A short time before I left Mexico, the rail was torn down, the monument upset, and, on the same night, the newly-buried body of a Scotchman was disinterred, stripped of its clothes, and thrown over the wall of the cemetery!