Question: Which city along New Jersey Route 4 was renamed in 1921?

Context paragraphs:
New Jersey Route 439: Route 439 is a short state highway in the communities of Linden and Elizabeth in Union County, New Jersey.  The highway is known as the Bayway, North Avenue and Elmora Avenue from the Goethals Bridge and Interstate 278 in Linden and does a loop around Elizabeth, with the designation terminating at an intersection with New Jersey Route 27 in Elizabeth.  The highway originated as part of Route 28 south of the current intersection with New Jersey Route 28 and Route S24 (which made up several routes) north of that intersection to New Jersey Route 82.  The current designation of NJ 439 was assigned in the 1953 renumbering.

New Jersey Route 67: Route 67 is a short state highway entirely within the community of Fort Lee in Bergen County, New Jersey.  It is part of the original alignment of U.S. Route 9W.  The road runs 1.86 mi from an intersection with Central Boulevard in Fort Lee (also designated as Route 5) down Palisade Avenue in downtown Fort Lee.  There it becomes known as Lemoine Avenue, terminating at an interchange with U.S. Route 9W, the Palisades Interstate Parkway and New Jersey Route 445S in Fort Lee.  The route was designated originally as a portion of State Highway Route 18N in 1923, and was split up in 1929 as part of current-days New Jersey Route 63, U.S. Route 9W and Route 67 for Routes S-1, 1 and Route S1A.  Route S-1-A remained intact on Palisades and Lemoine Avenue until the 1953 state highway renumbering when it was switched over to Route 67.  The route has remained virtually intact since.

New Jersey Route 158: Route 158 (also known as the Centre Street Bridge) was a short state highway in Newark and Harrison, New Jersey, in the counties of Essex and Hudson, which are located in the United States.  The Centre Street Bridge was first constructed in 1834 as a single-level railroad bridge.  However, in 1911, almost eight decades later, a second, upper level was constructed for rapid transit.  In 1937, the Hudson and Manhattan Railroad, now part of the Port Authority Trans-Hudson line, was realigned onto railroad tracks along New Jersey Route 21.  The upper level of the bridge was abandoned for this purpose, and was later converted to roadway.  At the western end in Newark it ran just south of Park Place, beginning at Center Street.  The route headed eastward, crossing over Route 21 and the Passaic River before entering Harrison, where it terminated at Second Street north of New Jersey Railroad Avenue.

Hackensack, New Jersey: Hackensack is a city in Bergen County, New Jersey, United States, and serves as its county seat.  The area was officially named New Barbadoes Township until 1921, but it was informally known as Hackensack.  As of the 2010 United States Census, the city's population was 43,010, reflecting an increase of 333 (+0.8%) from the 42,677 counted in the 2000 Census, which had, in turn, increased by 5,628 (+15.2%) from the 37,049 counted in the 1990 Census.

New Jersey Route 4: Route 4 is a state highway in Bergen County and Passaic County, New Jersey, United States.  The highway stretches 10.83 mi from Route 20 (McLean Boulevard) in Paterson east to an interchange with Interstate 95, U.S. Route 1/9, U.S. Route 46, and U.S. Route 9W at the George Washington Bridge approach in Fort Lee.  The route is a four- to six-lane 40 to divided highway its entire length, with the portion east of the Route 208 interchange in Fair Lawn a partial freeway consisting of interchanges and right-in/right-out intersections with a few businesses along the road, particularly in Paramus, where the route passes through a major shopping area consisting of numerous malls, Hackensack, Englewood, and Fort Lee.  West of Route 208, the route is a surface arterial that runs through commercial areas.  Route 4 intersects many important roads, including Route 208 in Fair Lawn and the Garden State Parkway and Route 17 in Paramus.  The highway is officially named the Mackay Highway, but is rarely referred to as such.

Dhankawadi: Dhankawadi is an outlying borough of the city of Pune in the state of Maharashtra.  It lies on the southern edge of the city along old Route 4 just north of where the Route 4 by-pass leaves old Route 4, about 6.5 km south of the Pune city centre.

New Jersey Route 154: Route 154 is a 1.70 mi long state highway in Cherry Hill Township, Camden County, New Jersey.  The route begins at an intersection with County Route 561 in Cherry Hill, heading northward to the site of the former Ellisburg Circle, where Route 154 reaches its northern terminus at New Jersey Route 41 (Kings Highway) and New Jersey Route 70.  The route ends concurrent with Route 41 for the short distance from the junction between the two routes.  Brace Road is the local name for Route 154 for its entire length.

New Jersey Route 59: Route 59, at 0.15 mi long, is the shortest state highway in New Jersey, United States.  The route consists entirely of a short block of Lincoln Avenue from Union County Route 610 (known locally as South Avenue) in Cranford to New Jersey Route 28 (known locally as North Avenue) along the Cranford–Garwood border.  The route functions as an underpass under the Raritan Valley Line of New Jersey Transit, under which it crosses about halfway down the block, along the municipal border.  Route 59 was originally a proposed alignment of Route 22, which was supposed to head from an intersection with current day New Jersey Route 159 in Morris County at the Pine Brook Bridge before heading through several counties, terminating at an intersection with New Jersey Route 27 in Rahway.  Most of the route was not constructed, and a portion in Garwood and Cranford was re-designated Route 59 in the 1953 New Jersey state highway renumbering on January 1, 1953.

New Jersey Route 44T: Route 44T, also known as the Gloucester County Tunnel, was a proposed state highway and vehicular tunnel during the 1930s from Gloucester County, New Jersey to Philadelphia County, Pennsylvania.  The route was to begin at the state line near Paulsboro, New Jersey, heading eastward as a freeway through several southern New Jersey communities and providing access from New Jersey Route 42 to the Delaware River.  The plans for the original freeway date back to 1930, when the original studies and requests were decided on by the New Jersey State Legislature.  Plans soon followed in Pennsylvania, but after three years of receiving approval, the Gloucester County Tunnel experienced several setbacks.  In 1938, the New Jersey State Legislature designated the State Highway Route 44-T designation, as a suffixed tunnel spur of New Jersey Route 44.  By the 1953 renumbering, Route 44-T was already repealed and decommissioned while the tunnel was never constructed by the Gloucester County Tunnel Commission.

New Jersey Route 303: Route 303 was a proposed state highway in the northeastern portion of New Jersey.  The route originally was defined to go from an intersection with current-day New Jersey Route 4 in Teaneck, then progressing northward through several local communities before connecting to the New York state line at Northvale.  At the state line, Route 303 was to intertwine and become the current-day New York State Route 303.  The alignment runs along the current alignment of County Route 505, which becomes NY 303 at the state line.

Supporting paragraphs: New Jersey Route 4 Hackensack, New Jersey
Answer: Hackensack