In the mid-19th century, few banking options existed for the growing number of manufacturers in the city of Buffalo.

As a result, businessmen Pascal Pratt and Bronson Rumsey founded M&T Bank in 1856 as "Manufacturers and Traders Trust Company".

[10] The company opened its first office on August 29 of that year at 2 East Swan Street in Buffalo.

[10] In 1901, the bank built a new headquarters on a site purchased for $210,000 near the southwest corner of Main and Swan Streets in Buffalo.

In 1917, Harry T. Ramsdell, the bank's fourth president, served as a district chairman for a special subscription committee of the national Liberty Loan program.

Harriman and a group of investors including A. H. Schoellkopf, from the founding family of the Niagara Mohawk power company, and James V. Forrestal, who would become the first U.S. Secretary of Defense, own enough shares to control both Fidelity and M&T.

In 1983, the bank which had assets of $2 billion and operated 60 offices, named Robert G. Wilmers as chairman and CEO, a position he held until his death in December 2017.

[12] In June 2014, a U.S. District Judge ordered M&T Bank to forfeit $560,000 that had been laundered through its Perry Hall, Maryland, branch; from 2011 to 2013, Deanna Bailey went to the branch and had head teller Sabrina Fitts convert cash amounts from $20,000 to $100,000 into larger bills.