 Present-day Route 109 was designated as a part of pre-1927 Route 14 in 1917 before becoming the southernmost portion of Route 4 in 1927. By the 1940s, US 9 extended south to Cape May from Absecon along this part of Route 4. In 1953, the Route 4 designation was dropped from this segment of road to avoid the concurrency with US 9. In 1972, US 9 was rerouted to head to the Cape May – Lewes Ferry terminal, with the former alignment into Cape May becoming Route 109.
