Where It All Goes Down
A Small Seaport Town in New England, 1865-1866
Even though O'Neill was clear that he wanted to create a modern psychological drama, he decided to set the story in the past. His re-creation of New England after the Civil War is pretty accurate. As one critic commented, "O'Neill has been at pains to make his image of post-war New England faithful in spirit and fact to what it was. Without much apparent research and with stringently economic means he has created the past: a song, cannon shots celebrating the surrender, a few names from history, lilacs, almost inevitably associated through Walt Whitman's elegy with the death of Lincoln." (Source)
But if you typed "New England" into Google Maps you wouldn't get directions that were very helpful. That's because New England is a term that lumps together the states of Maine, Vermont, Connecticut, Massachusetts, New Hampshire, and Rhode Island. Sure, they're all pretty small, but O'Neill still isn't being super specific.
Being the first place that most colonists settled in the U.S., New England has more than its share of old, established families of British descent who'd been around long enough to accumulate wealth and prestige. It was largely settled by the Puritans, who had a reputation of being, well, Puritanical when it came to things like sex, marriage, and class. New England has a lot of old seaport towns (because it has a lot of coastline), and this sets the tone for the themes of travel and seafaring that we see in the play. Boston Harbor seems to be the point of departure and arrival for the sailing ships in the plays.
While he did want his play to reflect the culture and experience of life in a small nineteenth-century New England town with its wealthy upper-crust aristocrats and its worker bees, he also wanted to do what the classic Greek playwrights were doing when they wrote their stuff. That means that he wanted to use his play to talk about the human condition, about struggles and ideas that weren't necessarily unique to a specific time and place but that everybody anywhere could understand and relate to. That's why he doesn't get too specific. O'Neill wants to make sure things seem kind of universal.
Most of the action in the play—except for a few secretive jaunts to the harbor in Boston—takes place either in or around the Mannon estate. The first act of every part of O'Neill's trilogy happens outside of the Mannon estate and, as the plot thickens and things start to get interesting, we journey further into the interior of the home.
We're with the Mannons when they've got company (usually in the sitting-room) or when they're having some personal chats (usually in the study). We even get a glimpse into Christine and Ezra's bedroom for what's probably the coldest and darkest moment of all, when Christine murders her husband. There are exceptions to this rule, like the nasty arguments that sometimes take place in front of the old mansion. But generally, the darker and more intense or dangerous something is, it's going down somewhere deep inside the house, hidden from public view.
The house itself, we're told over and over again, is dark and oppressive, like a tomb. It's almost a character in the play.