Chatham is a borough in Morris County, New Jersey, United States. As of the 2010 United States Census, Chatham's population was 8,962, reflecting an increase of 502 from the 8,460 counted in the 2000 Census that in turn, had increased by 453 from the 8,007 counted in the 1990 Census.
The area that is Chatham has been inhabited by humans for thousands of years. During historic times, Europeans began trading with the Native Americans who farmed, fished, and hunted in the area when it was claimed as part of New Netherlands. The community that now is Chatham was first settled by Europeans in 1710 within Morris Township, in what was then the English Province of New Jersey. The community was settled because the site already was on the path of a well-worn Native American trail, the location of an important crossing of the Passaic River, and being close to a gap in the Watchung Mountains. The residents of the English community changed its name from John Day's Bridge to Chatham, New Jersey in 1773.
Chatham's residents were active participants in the American Revolutionary War, which ended in 1783.