Adoniram J. Atwood was born on March 27, 1837, in Plymouth, Massachusetts, to John and Hannah Atwood. His father was a mechanic who owned $4,000 of real estate and $300 of personal property by 1860. He grew up and attended school in Plymouth. He married Helen Barnes around 1858, and their daughter Helen was born around 1859. They lived in Plymouth, and he worked as a trader and grocer. By 1860, he owned $1,500 of personal property. A decade later, he owned $5,000 of real estate and $5,000 of personal property.
In the 1880s, one writer observed that Atwood was “prominent among the old, well known, popular business men and native citizens of Plymouth.” His 1200-square-foot store contained a “full stock of all kinds of goods…including everything in choice staple and fancy groceries, and also dry and fancy goods.” He also conducted a “large business as a dealer in flour, feed, hay, grain, wood, and cedar posts.” He died in Plymouth in 1918.