The Georges Bank was incorporated on Feb 14, 1852 with a capital of $50,000. Edward O’Brien was one of seven original directors and the institution’s first president and largest stockholder.

During the later failure of the Pacific Bank of Boston, both the Thomaston and George's National Banks had their funds locked up in that institution. Mr. O’Brien promptly supplied funds to the George's National and offered aid to the Thomaston National Bank. Banks became national banks in 1865, one of numerous developments arising from Civil War fiscal needs.

In 1865 the bank became the George's National Bank. Following Edward O’Brien’s death in 1881, he was succeeded by his son, Edward Ellis O’Brien.

In 1888 The George's National Bank bought an undivided half of the eastern apartment of the Union Block from Sanford Delano, saloon keeper, and moved its quarters from the Carr O'Brien Block.