The Sunken Meadow Spur Parkway was first proposed in 1928 when the Town of Smithtown deeded over 400 acres (160 ha) of land to the Long Island State Park Commission via public vote.

Due to land use restrictions in Nassau County, Sunken Meadow was the first park east of New York City, because provisions for a parkway would be near impossible to build.

As part of the parkway opening, improvements were made to Sunken Meadow State Park, including expanded vehicle capacity and a longer boardwalk.

As is the case with most other parkways in New York, commercial vehicles are prohibited from using the Sunken Meadow, with an exception for the portion north of NY 25A.

This exit, which is only served northbound, connects the Sunken Meadow to NY 454 (Veterans Memorial Highway) via Harned Road, a local street in Commack.

The four-lane parkway continues north out of the interchange, immediately entering exit SM3A, which northbound connects to County Route 14 (CR 14; Indian Head Road).

[2] In Kings Park, the Sunken Meadow State Parkway bends northward, crossing under the Long Island Rail Road's Port Jefferson Branch and entering exit SM4.

After the interchange with CR 11, the Sunken Meadow enters Fort Salonga as a four-lane parkway with a wide median, bending northeast into exit SM5.

The parkway continues north through Sunken Meadow State Park and terminates at a roundabout near the Long Island Sound.

[7] On April 1, 1957, the Long Island Parks Commission opened the full alignment of the Sunken Meadow State Parkway to traffic, after an $11 million (1957 USD) construction project on the 7-mile (11 km).