Essentially correct. "Published" is the most important word in the
sentence.

http://www.copyright.cornell.edu/resources/publicdomain.cfm

DDD

PS: Under the US laws before 1870, and also for the period 1871-1909,
I'm not sure that articles written for newspapers at that time, unless
individually registered for copyright, would have had any route to (c)
protection in the first place.