 What is now Route 47 was originally designated as a segment of pre-1927 Route 15 between Rio Grande and Millville in 1917, and as one of two branches of pre-1927 Route 20 between Millville and Westville in 1923. In the 1927 New Jersey state highway renumbering, Route 47 was legislated to run from Route 50 in Tuckahoe to Brooklawn, following present-day Route 49 between Tuckahoe and Millville and its current alignment north of Millville. Meanwhile, the present-day alignment of Route 47 between the current Route 83 intersection in South Dennis and Millville was designated a part of Route 49 while the current alignment between South Dennis and U.S. Route 9 / Route 4 in Rio Grande became Route S49, a spur of Route 49. In 1933, the New Jersey Legislature named Route 47 Delsea Drive after a reporter for the Woodbury Times joked how the road connected the DELaware River to the Atlantic SEA. Route S49 was extended from Rio Grande to Park Boulevard in Wildwood in 1938. In the 1953 New Jersey state highway renumbering, Route 47 and Route 49 switched alignments south and east of Millville and Route 47 replaced Route S49 south to Wildwood.
