Because his subject was deceased, Trumbull used for his model Mercer's son Hugh Jr.; he twice sketched the young man in Fredericksburg, Virginia, in April 1791.
General Hugh Mercer, Jr., 1791
The issue of taxation had immense symbolic importance on both sides of the Atlantic. Like most of his fellow members of Parliament, [Lord Frederick] North regarded the right of Britain to tax America as integral to the absolute and indivisible supremacy of Parliament over America. The concept of parliamentary sovereignty was more than an abstract doctrine. It had emotional resonance as a constitutional victory won against the monarchy in the Glorious Revolution, following the deposition of James II in 1688. It was regarded as essential for the protection of liberty in general. For Britain, the right to tax the colonies was fundamental to its authority to govern America. At the same time, taxation united colonial opposition more than any other grievance.