Abijah Mann II. (1761-1856) came to Fairfield in 1785 and settled about a mile west of what would become Fairfield village. Abijah married Levina Ford of Austerlitz in 1786 and they had nine children. His second wife was Rachel Wilsey. Abijah participated in town activities and held several positions of responsibility. In 1803 he was a charter trustee of Fairfield Academy. In the Fairfield locality, Abijah Mann II. became known as Abijah Sr., and his son, Abijah III., was called Abijah, Jr.

Abijah, Jr. (1793-1868) graduated from Fairfield Academy and taught school for three years. For a few years he engaged in business in Seneca Falls, where he erected a block of buildings and served as postmaster. When he returned to Herkimer County, he studied law in the office of Hiram Nolton. While serving in the state assembly, Abijah Mann, Jr. helped establish New York State's banking laws.

In 1832 and 1834, Abijah Mann, Jr. was elected to Congress where he earned the respect of Martin Van Buren and other prominent Democrats.

From 1836-1842, he practiced law in Frankfort, NY, and then moved to Brooklyn where he specialized in bank receiverships with his son-in-law, John H. Rodman.

The brother of Abijah Mann, Jr. was Charles Addison Mann (1803-1860). He married Emma Bagg of Utica and became known as a fine real estate lawyer in Oneida County. He was elected to the Assembly and later the Senate in 1850 and served on the boards of academies and asylums in Utica.

One of Charles and Emma Bagg Mann's children was Matthew Derbyshire Mann. Matthew was born in Utica in 1845, graduated from Yale in 1867, and studied medicine under his maternal uncle, Dr. M.M. Bagg. He graduated from the College of Physicians and Surgeons at Columbia, studied abroad, and lectured at several medical colleges in the United States.

In 1882 he joined the University of Buffalo, appointed to fill the vacancy caused by the death of Dr. James P. White. In 1901 Dr. Mann was called to attend President William McKinley when he was shot at the Pan-American Exposition in Buffalo.