The bridge is jointly owned by the Federal Bridge Corporation and the Saint Lawrence Seaway Development Corporation. It is operated by the Seaway International Bridge Corporation, which came under the control of the Federal Bridge Corporation from the Saint Lawrence Seaway Authority in 1998.
Previously known as the Cornwall-Massena International Bridge, the SIB was a private bridge whose outstanding stock was purchased by the Saint Lawrence Seaway Authority (Canada) and the Saint Lawrence Seaway Development Corporation (U.S.) in 1957. It was incorporated in Canada five years later.
The bridge consists of the South and North Channel Bridges. The South Channel Bridge was opened in 1958, and spans the St. Lawrence Seaway. The North Channel Bridge, opened in 1962, connects the City of Cornwall to Cornwall Island.
In 2000, the international border crossing that the Seaway International Bridge comprises was named the Three Nations Crossing, in honor of the Mohawks of Akwesasne who inhabit the region. en.wikipedia.org/wiki/Seaway_International_Bridge