The most powerful earthquake to strike New Jersey was the one that occurred at 9:00 PM on 29 November 1783. It measured 5.3 on the Richter scale, and VII on the Mercalli intensity scale. It was felt from New Hampshire to Pennsylvania.
In Philadelphia, it was reported that items were thrown off shelves and sleeping people were woken up.
Maryland Gazette, 11 Dec 1783, page 2
Damaging Earthquakes Felt in NJ
Historic Earthquakes: New Jersey 1783 11 30 03:50 UTC (Local 11/29)
"Philadelphia, December 2." Maryland Gazette, 11 December 1783, p. 2.
1783 New Jersey earthquake
Weather trivia: The day New Jersey shook like no other