Let's just go ahead and say this straight up: in this book, birds represent freedom. Is it a coincidence that a book called Freedom is based around a small blue bird that migrates between North and South America? No, it doesn't seem to be a coincidence at all.
Franzen addresses this most directly in the book's final section, "Canterbridge Estates Lake." The birds that have long thrived in the area (i.e., around The Lake Formerly Known As Nameless Lake), and that Walter has loved watching since he was a teenager, are now being slaughtered by the cats belonging to Walter's new neighbors.
He tries doing something about the threat, and encourages his neighbors to keep their cats inside, and distributes "bibs" for the cats that hinder their ability to hunt (making him look all the crazier, but whatever). But nothing works.
Finally, when Walter and Patty move out, they donate their land to a local land trust, to become a bird sanctuary. In other words, these birds have always been free, but this area's no longer safe for them. They literally have to be kept in a big cage, to protect them from the new threats they face. Is this an endorsement of the Patriot Act's restriction of civil liberties? Or a call for greater awareness of the damage wasteful modern lifestyles are having on the planet? Maybe both? Or maybe not.
We're just going to mention a few things here and let you come to your own conclusions: Richard's last name is Katz. He's a predator. Cats are also predators. They eat birds. Katz doesn't eat birds, but he sure "devours" young women, who are often derogatively called "chicks" or "birds." Walter loves birds; he wants to take care of them and fight for their rights. Walter is also a feminist. Richard cares not for birds. And did we mention his last name is "Katz"? Meow.
Symbol: The Fiend of Athens
Here's an easy one: On their first real "date" back in college, Walter and Patty go see an old Greek movie called The Fiend of Athens. Here's how Patty remembers it going:
[T]he plot of The Fiend of Athens concerned a mild-mannered accountant with horn-rimmed glasses who is walking to work one morning when he sees his own picture on the front page of a newspaper, with the headline FIEND OF ATHENS STILL AT LARGE. Athenians in the street immediately start pointing at him and chasing him, and he's on the brink of being apprehended when he's rescued by a gang of terrorists or criminals who mistake him for their fiendish leader. The gang has a bold plan to do something to them that he's just a mild-mannered accountant, not the Fiend, but the gang is to counting on his help, and the rest of the city is so intent on killing him, that there finally comes an amazing moment when he whips off his glasses and becomes their fearless leader – the Fiend of Athens! He says, "OK, men, this is how the plan is going to work." (2.2.577)
Well you might read that description and think to yourself, Hey, that's just like Walter. He's really timid and polite, and Patty wants nothing more than for him to be a dangerous rebel (that is, be more like Richard). But you've only got about two seconds for this thought to flash in your mind, because in the next paragraph Patty pretty much says exactly that, imagining him "whipping his glasses off like that" (2.2.578).
But still, you're thinking, Wow, that movie really could be about Walter, because the more the book goes on, the angrier he becomes, and he sure is a bit of a revolutionary. Well then Franzen goes and steals your brilliant idea by naming the final chapter of the book's third section "The Fiend of Washington." Walter finally does embrace his inner volcano, becoming the angry madman he's had boiling inside him for so long.
Luckily for him, this fate is happier than the Fiend of Athens. Although Patty seems to have tuned out the ending, in the movie the gang realizes he isn't who they thought he was and he gets killed. Walter might delicately place his rage back in the bottle, but at least he makes it out alive. (Read more about the movie here.)
Symbol: Walter and the Coal Companies
There are two main plotlines involving Walter. In one, he enters into a relationship with someone, and that person betrays him and has an affair with someone else. In the other one, he enters into a relationship with someone, and that person betrays him to go behind his back with someone else.
Wait, say what? Well, he's married to Patty, and Patty has an affair with Richard. He also has an agreement with Vin Haven to create nature reserves in West Virginia, and Haven makes a side deal with a few big corporations to mine those areas for natural gas. Interesting how similar these romantic and non-romantic entanglements are. Is Walter's marriage a representation of his environmental work? Or does his environmental work symbolize his marriage?
The terrorist attacks of September 11, 2001 hang over this book just as they've hung over Americans' lives. The first reference to "the great national tragedy" (1.1.137) is right in the introductory chapter, as the Berglunds prepare to sell their house and move to Washington, D.C. That it immediately follows a mention of a "Gore/Lieberman" sign still stuck in the Berglunds' yard ties the attacks to the fateful election of George W. Bush in 2000 (1.1.137).
Since much of the action in the book takes place in 2004, we don't get that much dialogue about 9/11. Instead, the weeks and months following the attacks are evoked by a few poignant images scattered through the text. We discuss Joey Berglund's uniquely cranky view in "Characters," but the descriptions of scenes on his college campus are affecting in and of themselves:
In the days after 9/11, everything suddenly seemed extremely stupid to Joey. It was stupid that a "Vigil of Concern" was held for no conceivable practical reason, it was stupid that people kept watching the same disaster footage over and over, it was stupid that Chi Phi boys hung a banner of "support" from their house, it was stupid that the football game against Penn State was canceled, it was stupid that so many kids left Grounds to be with their family [...] The four liberal kids had endless stupid arguments with the twenty conservative kids, as if anybody cared what a bunch of eighteen-year-olds thought about the Middle East. A stupidly big fuss was made about the students who'd lost relatives or family friends in the attacks, as if the other kinds of horrible death that were constantly occurring in the world mattered less, and there was stupid applause when a vanful of upperclassmen solemnly departed for New York to give succor to the Ground Zero workers, as if there weren't enough people in New York to do the job. Joey just wanted normal life to return as fast as possible. (3.2.3)
A few months later, when Joey travels to Manhattan, he is no longer protected by the gilded walls of a college campus and has a more intense experience of the new world order:
Solemn firefighters nodding to the crowd assembled by a 9/11 shrine outside a station house. [...] National Guard troops patrolling Grand Central with highly advanced weapons [...] each encounter was like a poem he instantly memorized. (3.2.510)
Interestingly, however, even though Joey claims he would like see the wreckage at Ground Zero (3.2.417), something (perhaps his youth?) prevents him from actually doing so. Richard Katz, on the other hand, is world-weary and cynical enough to stand on a rooftop downtown and survey the devastation of the "pinch point of the world [...] the World Trade Center cicatrix" (3.1.65).