The Raritan River Rail Road (reporting mark RR) was a 12-mile (19 km) shortline railroad in Middlesex County, New Jersey U.S., Founded in 1888, it was based in South Amboy, from which it ran west as far as New Brunswick.

The Raritan River Rail Road was built when the peak of the U.S. railroad building fever was subsiding in the late 1880s.

At the first meeting of the board of directors in April 1888, Edward H. Ripley was elected president, E. W. Harrison was appointed Chief Engineer, and a construction contract to build the railroad was awarded.

Suchs was a sand and clay industry that already had a very long siding from the Pennsylvania Railroad's old C&A line in Sayreville (connected a few miles west of today's Browns Yard).

Disputes with workers and clashes with local landowners during the construction of the Raritan River Railroad sparked sometimes heated conflict.

One contractor, Charles Van Houghton of Jersey City, was hired to grade the road and lay stone culverts at South Amboy.

The unpaid workers went on strike as a result, and the sheriff confiscated Van Houghton's equipment so that the payroll could be met.

A local brick manufacturer, Noah Furman, owned land needed by the railroad for the extension of its line from Sayreville to South River.

[6][7] Coverage of the Sayreville Riot arrests was sensationalized by the press, with the New York Times falsely reporting on September 16, 1889, that indictments of all officers of the Raritan River Railroad were expected in the case.

By July 4, 1891, the RRRR's first train left Milltown, and shortly thereafter the line reached New Brunswick, having laid twelve miles (19 km) of mainline track.

The railroad decided not to cross the Raritan River into New Brunswick to reach Bound Brook, due to the expense and lack of potential freight business at the time in the largely undeveloped area.

Although wholly owned by the two bigger lines, the RRRR was locally managed from its headquarters on John Street in South Amboy.

Crossman's in Sayreville grew so large that a narrow gauge line running in the pits brought the sand and clay to the connection with the RRRR.

During this same period, the current Sanford Street terminus in New Brunswick was finished, with elaborate brick passenger and freight stations.

[11][12] In addition to munition plant shipments along the line, World War I also resulted in a substantial increase in passenger traffic.

The 1920s saw a decline in freight and passengers, with increased competition from buses, cars, and trucks beginning to have an adverse effect upon the RRRR.

Revenue traffic fell by half and passenger service was reduced considerably, to just four daily trains by 1930, compared to 22 in 1917.

As of April 27, 1936, the Raritan River had only one scheduled round-trip passenger train, operating daily except Sundays between Parlin and New Brunswick.

By 1937, the multitude of sand, clay, and brick industries that contributed greatly to the Raritan River's success in the early years were virtually all gone.

22, was also scrapped in 1937, ending baggage service on the Raritan River Railroad and leaving the line with just one passenger car, No.

The North Jersey Chapter of the NRHS sponsored a special excursion train on May 28, 1938, over the Raritan to mark the passing of regular scheduled passenger service.

The special train left New Brunswick at 2:40 pm, stopped at the Lawrence Brook Trestle for photos, then proceeded up the Serviss Branch where it parked at Hendersons Siding just 15 feet (4.6 m) away from the Route 18 crossing.

The special then proceeded back down the main and headed to South River, where participants observed the only manually hand-cranked swing bridge in New Jersey.

After the war's end, the RRRR purchased seven surplus US Army engines for only $100,000, allowing the retirement of the line's elderly locomotives.

A temporary boost in tonnage on the Raritan occurred because of construction of the New Jersey Turnpike, which generated fill material and sand movements.

The Raritan River also derived revenue from high per diem rates, leasing 100 fifty-foot box cars in 1975.

The line was then cut back to the Phoenix Spur, which currently receives freight in the form of scrap steel.

In the 1980s and 1990s, some of the largest customers ceased shipping by rail: Dupont stopped receiving deliveries and their siding is now disconnected.

In October 2014, the siding at the former National Lead site was reactivated for the shipment of radiologically contaminated soils to out-of-state disposal facilities.

It is in a deteriorating condition and plans are being made by the Raritan River Chapter of the NRHS and the Borough of Milltown to move it to another location and restore it.