The borough of Groton Long Point as a summer resort area (and a traffic generator) dates back to the earliest days of numbered highways in the state. In the 1930s it was the largest resort area in the state east of the Thames River (a rather significant qualifier). A trolley line, the Groton and Stonington Street Railway, led to downtown Groton until it closed in 1928. State Highway 342 led to downtown Mystic.
Originally, only one connection to US 1
In 1932, SH 342 became Route 215, at the time one of the highest numbered routes in the state. This was roughly the eastern half of today's Route 215, a 3.38-mile route following some older roads (using today's road names):
- today's Groton Long Point Road, from the bridge over Palmer Cove to Marsh Road
- Marsh Road, to a north-south road crossing the railroad tracks near West View Avenue.
- The north-south road (no longer exists) to Prospect Hill Road
- Prospect Hill Road to Elm Street
- Elm Street, Noank Road and Water Street to US 1 in Mystic. This segment is part of today's Route 215.
"Dead-end" routes like the original 215 were more common in the past; Route 213 in New London was another original dead-end route.
At the time, South Elm Street and Groton Long Point Road, part of today's Route 215, did not exist. Brook Street was the way back to US 1 and points west. A few other Noank streets were state-maintained:
- SR 670: 0.45 miles of Prospect Hill Road, from Brook Street to Elm Street (Route 215)
- SR 670A: 0.21 miles of Ward Avenue, from Main Street to Front Street
- SR 670B: 0.12 miles, Mosher Street, over railroad tracks from Route 215 to SR 670A
The entrance road to Groton Long Point at the end of Route 215 was prone to flooding during hurricanes. In 1955, a bill was introduced to raise the road level about three feet, and add additional conduits for water flow under the bridge.
Almost traded away
On January 17, 1947, the city of Groton and the state approved a transfer of maintenance: the state would take over Crystal Lake Road, a connector from old Route 12 to new (Route 12) near the submarine base; and the city would take over all of Route 215. In 1952, area residents petitioned the city and state rescind the Route 215 plan, saying the state was better able to maintain it. In the end, Route 215 remained a state highway.
Extension toward Groton
In 1960, the state Committee to Reclassify All Public Roads recommended including Brook Street from Prospect Hill Road to US 1 in the state highway system. If left unsigned, this would have been an extension of SR 670; instead, the Route 215 designation was extended along this road back to US 1 in 1962.
Brook Street was the original connection from Noank and Groton Long Point toward downtown Groton, and US 1 at Fort Hill. Plans to create a straighter, safer connection date back to the 1930s.
In 1962 (or 1964), the new Brook Street opened, along with a new bridge over the railroad, and South Elm Street. An older railroad overpass, near West View Avenue, closed. Route 215 was moved from Marsh Street to South Elm Street, and from Brook Street to the new Brook Street.
Road name changes
A few area roads changed names, complicating historical research of Route 215.
On Jan. 2, 1965, the New Brook Street (an unofficial name) was named Veterans Memorial Highway – the consensus of a public hearing in autumn 1964.
In December 1964, some residents protested that name, and submitted a petition to use the name Groton Long Point Road ("GLPR") instead. This led to a second proposal, since that name was already in use, to rename the portion of existing GLPR east of Veterans Memorial Highway as an extension of Marsh Road.
Both changes eventually took place, so Veterans Memorial Highway no longer exists, and the Groton Long Point Road name was essentially reused.