A bookseller, then a bank cashier by trade, as a young man he began gathering the reminiscences of elderly people, and collected them in the first major history of the city. Annals of Philadelphia was published in 1830, with expanded editions in 1844 (two volumes) and 1857. A third volume by Willis P. Hazard was added in 1879, and the set continued to be published into the early 20th century.
He also published Historic Tales of Olden Time of New York City and State (New York, 1832), Historic Tales of Olden Time of Philadelphia and Pennsylvania (Philadelphia, 1833), and Annals and Occurrences of New York City and State (New York, 1846), among others
That fight was lost, but the shock of the building"s 1867 demolition — after Watson"s death — helped spark a historic preservation movement in Philadelphia. While Watson is readable, he is not always reliable, and his carelessness about citing sources is a frustration to scholars.
Still, it is because of him that we have the first-person accounts of people such as "Black Alice", an enslaved African woman reputedly born in Philadelphia 1686, who lived to age 116, and claimed to remember William Pennsylvania
He was a passionate advocate for preserving historic buildings.
Married Phebe Crowell, 1812, 7 children.