Erasmus and Eunice lived in Mystic, CT, and had several children. (according to A Genealogy of Williams Families)

The 1880 United States Census, Ledyard, New London, Connecticut, shows:

Erasmus Avery, Farmer-Selectman, age 58, born in Connecticut, both parents born in Connecticut
Eunice S. Avery, wife, age 51, born in Connecticut, both parents born in Connecticut.

Also in the household was Charles E. Spencer, age 11, relationship "Other"