From Holbrook's Pocket Guide 1872:

The Sentinel of Freedom, now the weekly edition of the Daily Advertiser, is the oldest paper in the State, published uninterruptedly down to our day.  The first number was issued, Wednesday, October 5th, 1796, nearly seventy-six years ago.  It was then about half the size of the present paper, and bore the motto, “The Public Will, our Guide—the Public Good our End.”  The contents consisted of “General Washington’s address to the people of the United States, declining to be again put in nomination for the Presidency,” and “Act to regulate the election of members of the legislative council and general assembly, etc,” “and editorial address to the public,” a poet’s corner containing a song, “On the merits of printing.” And two or three advertisements.  Its matter, however, soon became more varied.  With No. I of Vol II, a new motto was adopted, “The folio of four pages, happy work! What is it but a map of busy life, its fluctuations and its vast concerns?” and again it was changed in No. XXXIII, vol. VI, May 5th, 1801, to quotation from Jefferson, “Errors of opinion may be tolerated where reason is left to combat it.”  The columns of the two last numbers of the last century were bordered with black in mourning for the death of Washington, which occurred Saturday, December 14th, 1799, and whose address had graced the first page of the first issue of the Sentinel.  The paper has always been a favorite and has a large circulation, both in town and country.

From "Essex County, NJ, Illustrated 1897":

The Sentinel of Freedom was the weekly edition of the Daily Advertiser. The paper had it's centennial anniversary on October 5, 1896. It was the second weekly paper to be published in Newark, and was among the first to be published in the State.