The Camden, Ellisburg, and Marlton Turnpike was chartered in 1849 as a
turnpike that was to run from Camden east to Marlton along what is today Route 70 and Browning Road (CR 612)/Marlton Pike (CR 601). The Marlton Pike was taken over by Camden County in 1907 at a time many other turnpikes became public roads. The current alignment of Route 70 between
Whitesbog (the west end of the concurrency with CR 530) and Lakehurst was legislated as a part of pre-1927 Route 18 in 1923, a route that was to run from
Camden to Toms River. In the
1927 New Jersey state highway renumbering, Route 40 was designated to run from Camden to Lakewood along the current alignment of Route 70. In addition a spur of this route called
Route S40 (now Route 72) was designated to head from the route at the Four Mile Circle to
Manahawkin. Eventually, the eastern terminus of Route 40 was moved to the
Laurelton Circle in Brick, where it intersected Route 35 (now Route 88) as well as Route 34, which continued north from this point. The western terminus was placed at the
Airport Circle with
US 30 and
US 130 in Pennsauken, ending concurrent with Route 38. In the
1953 New Jersey state highway renumbering, Route 40 was renumbered to Route 70, to avoid conflicting with
US 40 in the state. Also, Route 70 was designated onto its current alignment between Route 38 in Pennsauken and Route 34 and Route 35 at the Brielle Circle, removing the concurrency with Route 38 and replacing the portion of Route 34 between the Laurelton Circle and the Brielle Circle. Since 1953, many changes have occurred to Route 70. Several traffic circles that had existed on the road had been either modified or replaced by at-grade intersections. The Marlton Circle at Route 73 in Marlton was modified in 1974 to allow Route 73 to run straight through the circle. This circle became known for traffic backups and was later replaced with an interchange. Construction on this interchange, which cost $31 million, began in April 2009. The interchange was completed in June 2011. The Laurelton Circle at Route 88, built in 1937, was replaced by the 1990s. The
Ellisburg Circle at Route 41 and Route 154, was replaced by an intersection with
jughandles. In conjunction with eliminating the Brielle Circle, Route 70 was also widened between the intersection with Jack Martin Boulevard in Brick Township and the former circle. In July 2004, floods caused by heavy rain washed away a bridge along the route in Southampton Township, leading for it to be replaced. The New Jersey Department of Transportation replaced the September 11th Memorial Bridge over the Manasquan River in a $52 million project that increased capacity on the bridge, added monumental decorations, and increased pedestrian access. Construction was completed in September 2008, two years ahead of schedule. In September 2021, NJDOT began a project to repave and reconstruct the section of Route 70 between Route 38 in Pennsauken Township and Cooper Avenue in Evesham Township. The project will include reconstructing jughandles, upgrading traffic signals, improvements to drainage systems, utility improvements, and pedestrian improvements. The reconstruction project is planned to be completed in early 2027. ==Major intersections==