Woodstock festival - A concert takes place at farm (which belongs to Cletus) and expensive damage occur.
Altamont Free Concert - Babies wear traditional Hippie clothes and dance naked. They also lend themselves pacifier and then they all are in euphoria, just like after using drugs.
Marge readily understands and speaks the kids' Pig Latin, though she failed to understand Homer's Pig Latin in The Front - apparently she mastered the language between the two shows.
When Bart and Lisa fight over the control of the remote, they accidentally switch over to King of the Hill, where Hank Hill can be heard in the background saying, "Bobby, I've got propane in my urethra." which pokes fun at Hank's character (Hank has a son named Bobby, sells propane and propane accessories, and was diagnosed with a narrow urethra).
At the beginning of the episode, Bart watches TV. The program is called The Gator Baitor. It's an obvious parody of the Crocodile Hunter, complete with a Steve Irwin-esque host, he meets his end at the mouth of a crocodile.
When Maggie has the long handled pliers and grabs Homer by the nose, he rolls over and screams out just like Curly Howard.
The news report on the baby riot is accompanied by a graphic which reads "The Tot Offensive," a reference to the 1968 Tet Offensive.
At the end of the episode, the members of Lindsey Naegle's group are defeated by the hugs of children ("God's lowliest creatures"). This is a reference to The War of the Worlds, in which the Martians are defeated by bacteria ("God's lowliest creatures").
After the adults go on their rampage, a tearful Milhouse (with a blubbery lip and arched eyebrows) watches Moe reverse the "Я" in the Toys "Я" Us sign. His expression is a parody of a scene from the Frank Capra film Divide and Conquer. 
The toppling of the Itchy and Scratchy statue scene resembles the toppling of the Saddam Hussein statue.
The sentence pronounced by Lisa upon having defeated the voters is a reference to the final sentence of the movie based on The War of the Worlds which identify the defeat of a threat at the hand of infinitely smaller creatures ("The humblest things that God in his wisdom has put upon the earth").