[1] Although "the Hamptons" officially begins about 10 miles (16 km) west at Westhampton, New York, the Shinnecock Canal, which funnels traffic across bridges for the Sunrise Highway, Montauk Highway, and Long Island Rail Road, marks their beginning in popular imagination.

To alleviate tidal differences of 3 feet (0.91 m) and more between Peconic Bay to the north and Shinnecock Bay, construction of "tide gates" and bulkheading (not a canal lock as exists today [further explanation needed]) began in 1918.

This did not alleviate the difference in elevation between the canal's two ends but sought to mitigate it.

The lock increased the salinity levels in Shinnecock Bay which had nearly assumed fresh water proportions and was resulting in a dying off of its shellfish population even though it was separated from the Atlantic by a narrow barrier island.

Shinnecock Bay's salinity levels were solidified during Great Hurricane of 1938, which broke through the barrier island to form Shinnecock Inlet almost due south of the canal.