Branchville was incorporated as a borough by an act of the New Jersey Legislature on March 9, 1898, from portions of Frankford Township.

By the year 1844, it was a well-established community with 32 dwellings, mills, blacksmiths, an academy, a church and a variety of other factories and businesses.

Energy would later be harnessed from this dam and a second one that was built to supply Branchville with electricity and its own power company.

Extension of rail service on the Sussex Railroad to Branchville in 1869 brought an even greater boon to the community's economic growth.

The railroad had made it possible to ship products from the local mills and creameries to larger urban areas to the east.

As many as six trains a day would bring people from the larger cities to enjoy a country vacation.

This is a shale, slate, and limestone formation created 450 million years ago when a chain of volcanic islands collided with proto North America.

The islands went over the North American Plate, creating the Highlands of Sussex County and the Kittatinny Valley.

About 400 million years ago a small continent that was long and thin, collided with proto North America creating folding and faulting.

The Silurian Shawangunk conglomerate that was under a shallow sea, lifted due to pressure.

End moraines exist in Stokes State Forest, another just off Route 565 north of the Skylands Park and one about a mile south of Ross's Corner.

The 2010 United States census counted 841 people, 364 households, and 221 families in the borough.

[33] As of the 2000 United States census[15] there were 845 people, 354 households, and 225 families residing in the borough.

[6] The borough form of government used by Branchville is a "weak mayor / strong council" government in which council members act as the legislative body with the mayor presiding at meetings and voting only in the event of a tie.

The mayor can veto ordinances subject to an override by a two-thirds majority vote of the council.

[37][38] As of 2024[update], the mayor of Branchville Borough is Democrat Anthony Frato Sr., whose term of office ends December 31, 2027.

[3][39][40][41][42] In January 2015, the borough council appointed Steven Schechner to serve the term expiring in December 2018 that had been held by Frank J. San Phillip, who was elected but did not take office for personal reasons; Schechner will serve on an interim basis until the November 2016 general election, when voters will select a candidate to serve the two years remaining in the term of office.

[45][46][47] For the 119th United States Congress, New Jersey's 5th congressional district is represented by Josh Gottheimer (D, Wyckoff).

[50] For the 2024-2025 session, the 24th legislative district of the New Jersey Legislature is represented in the State Senate by Parker Space (R, Wantage Township) and in the General Assembly by Dawn Fantasia (R, Franklin) and Mike Inganamort (R, Chester Township).

At an annual reorganization meeting held in the beginning of January, the board selects a Commissioner Director and Deputy Director from among its members, with day-to-day supervision of the operation of the county delegated to a County Administrator.

[62] Among the borough's 2010 Census population, 66.1% (vs. 65.8% in Sussex County) were registered to vote, including 85.7% of those ages 18 and over (vs. 86.5% countywide).