Moore was Professor of Oriental and Greek Literature, as well as Divinity and Biblical Learning, at the General Theological Seminary of the Protestant Episcopal Church, in New York City.

Moore publicly claimed authorship in 1837, and this was not disputed during his lifetime, but a rival claimant emerged later and scholars now debate the identity of the author, calling on textual and handwriting analysis as well as other historical sources.

[3][4] Moore's maternal grandfather was Major Thomas Clarke, an English officer who stayed in the colony after fighting in the French and Indian War.

[7] One of Moore's earliest known works was an anonymous pro-Federalist pamphlet published prior to the 1804 presidential election, attacking the religious and racial views of Thomas Jefferson (the incumbent president and Democratic-Republican candidate).

[10] He later gave 66 tracts of land – the apple orchard from his inherited Chelsea estate – to the Episcopal Diocese of New York to be the site of the General Theological Seminary.

[11] After the seminary was built, Moore began the residential development of his Chelsea estate in the 1820s with the help of James N. Wells, dividing it into lots along Ninth Avenue and selling them to well-heeled New Yorkers.

In response to a query in 1829, Sentinel editor Orville Holley wrote that "We have been given to understand that the author ... belongs by birth and residence to the city of New York, and that he is a gentleman of more merit as a scholar and a writer than many of more noisy pretensions."

[22] In response to Foster's claim, Stephen Nissenbaum, professor of history at the University of Massachusetts, wrote in 2001 that, based on his research, Moore was the author.

Kaller has offered a point-by-point rebuttal of both Foster's linguistic analysis and external findings, buttressed by the work of autograph expert James Lowe and Dr. Joe Nickell, author of Pen, Ink and Evidence.

As first published in The Sentinel, the names of Santa's last two reindeer in the poem were Dunder and Blixem, and Foster argued the change to Donder and Blitzen in later versions was evidence of tampering by Moore with the "perfectly correct Dutch" of Livingston.

[29] But donder is the correct Dutch word for thunder, and the phrase was used by multiple English and American authors with a variety of different spellings in the late 1700s and early 1800s.

[30][31][32] In 2016, the matter was discussed by MacDonald P. Jackson, an emeritus professor of English literature at the University of Auckland, a fellow of the Royal Society of New Zealand and an expert in authorship attribution using statistical techniques.

In his 2023 book The Fight for "The Night": Resolving the Authorship Dispute over "The Night Before Christmas," retired litigator Tom A. Jerman reported using Duquesne University computer scientist Patrick Juola's Java Graphical Authorship Attribution Program to compare the poem to the works of Moore and Livingston, with 16 of 17 tests pointing to Moore as the likelier author.

When the government of New York City decided on a street grid in Manhattan, based on the Commissioner's Plan of 1811, the new Ninth Avenue was projected to go through the middle of the Chelsea estate.

He thought it was a conspiracy designed to increase political patronage and appease the city's working class, and argued that making landowners bear the costs of the streets laid through their property was "a tyranny no monarch in Europe would dare to exercise."

[37] Despite his protests, Moore was already preparing to develop Chelsea, acquiring adjacent plots of land from relatives and neighbors until he owned everything from Eighth Avenue to the Hudson River between 19th and 24th Streets.

Ten years later, Moore gave land at 20th Street and Ninth, east of the avenue, to the diocese for construction of St. Peter's Episcopal Church.