It was founded by eight men from across New York—General James S. Wadsworth of Geneseo, J. P. Beekman of Kinderhook, New York, John Arnot of Elmira, John Magee and Constant Cook of Bath, William R. Gwinn of Medina, and George Palmer and James M. Ganson of Buffalo.

The new institution was called Marine Bank because much of its early business depended on the economic vitality of Buffalo's lakefronts and riverfronts.

From the first day it opened its doors on August 27 at 79 Main Street, Marine was the prominent bank for the thriving grain and milling industry on the waterfront.

However, the diverse geographic base of the bank's eight founders indicated that they intended to expand across New York.

In 1994, Marine Midland acquired Spectrum Home Mortgage, which operated in eight states.

Then in 1995, Marine acquired United Northern Federal Savings Bank, with branches in Watertown and Lowville, New York.

That same year, Marine Midland acquired 11 branches from the East River Savings Bank in the New York Metropolitan area.

At the same time, HSBC transferred two branches in the northwestern United States to Hongkong Bank of Canada.

The next year, Marine completed its acquisition of First Federal Savings and Loan from Toronto-based CT Financial Services, for $620 million.

For all intents and purposes, HSBC had jettisoned the original core of Marine Midland.

As a result, Key owns most of the core of the old Marine Midland, with a small portion held by Northwest.

Key had been one of Marine Midland's main rivals in Upstate New York for much of the 20th century.