[1] Dubbed "Pennsylvania's first historian"[2][3] Proud was a Loyalist during the American Revolution, and completed much of his writing while living in poverty after emigrating from England to Philadelphia.

In order to support himself, he secured work as a tutor for several families, including that of Timothy Bevan of Hackney, with whom he resided for a number of years before emigrating from England in late winter of 1758.

[15] Briefly moderating his "views on 'the American cause'", according to Kara Flynn, Special Collections cataloguer at Haverford College, he "returned to his Loyalist roots" following a series of revolts by Patriot sympathizers.

He used this time to write poetry, translate Latin works into English, and perform significant research that would later form the backbone of his two-volume The History of Pennsylvania in North America.

[22] After soliciting and securing financial support from his students and other members of Philadelphia's Quaker community in order to continue his historical research and writing,[23] he was then able to release the second volume of this work the following year.

"[31] Also, from the perspectiveof Robert Bray Wingate, the former rare books librarian at the Pennsylvania State Library:[32] Proud had available to him historical resources which he chose to ignore and much of his work is marred by partisanship and bias.