What is now US 206 in New Jersey was designated as part of several state routes prior to 1927, including pre-1927 Route 2 between Bordentown and Trenton in 1916, pre-1927 Route 13 between Trenton and Princeton in 1917, and pre-1927 Route 16 between Princeton and Bedminster Township in 1921. The current routing along pre-1927 Route 2 became a part of US 130 in 1926. In 1927, current US 206 became Route 39 between Hammonton and White Horse, Route 37 between White Horse and Trenton, Route 27 between Trenton and Princeton, Route 31 between Princeton and Newton, and Route S31 between Newton and the Delaware River. In the later 1930s, US 206 was designated to connect US 30 in Hammonton north to US 6 and US 209 in Milford; the northern terminus was moved to its current location in the 1940s. The state highways running concurrent with US 206 in New Jersey were removed in 1953. In the 1960s, two separate freeways were proposed for US 206 but never built. The first freeway was to connect Hammonton south along the Route 54 corridor toward Route 55 and the planned Route 60 in Vineland and Millville. The other US 206 freeway was planned in northwestern New Jersey, connecting I-80 in Netcong north to Montague Township. Construction began for a bypass of US 206 around Hillsborough in 2010 after being planned since 1974. The NJDOT widened the route in Byram Township to alleviate congestion, with completion in 2013.