In 1791, he became the president judge of the Fifth Judicial District of Pennsylvania and possessed authority over both state and federal laws.

[2] Westward expansion at this time created new legal questions about the tax on whiskey, land ownership and battles with Native Americans.

This was to be important during the Whiskey Rebellion during which he upheld the authority of state and federal laws over Western Pennsylvania.

The collection includes correspondence between to Alexander Addison and Hugh Henry Brackenridge,[8][9][10] William Findley and Charles Nisbet.

Most of the collection contains discussions on political events in the United States and Europe, the Constitutional Convention, the Jay and Pinckney Treaties, battles with Native Americans wars, and the Whiskey Rebellion.