Joe, I have a copy of that article, or one like it, right here in my RUS book. Here's the list of "42" songs the Music Educators Nat'l Conference says every American should know:

Amazing Grace
America (My Country 'Tis of Thee)
America the Beautiful
Battle Hymn of the Republic
Blue Skies
Danny Boy
De Colores
Dona Nobis Pacem
Do-Re-Mi
Down by the Riverside
Frere Jacques
Give My Regards to Broadway
Good Bless America
God Bless the U.S.A.
Green, Green Grass of Home
Havah Nagilah
He's Got the Whole World in His Hands
Home on the Range
I've Been Working on the Railroad
If I Had a Hammer
Let There be Peace on Earth
Lift Ev'ry Voice and Sing
Michael (Row the Boat Ashore)
Music Alone Shall Live
My Bonnie Lies Over the Ocean
Oh! Susanna
Oh, What a Beautiful Mornin
Over My Head
Puff the Magic Dragon
Rock-A-My Soul
Sakura
Shalom Chaverim
She'll Be Comin' Round the Mountain
Shenandoah
Simple Gifts
Sometimes I Feel Like A Motherless Child
The Star-Spangled Banner
Swing Low, Sweet Chariot
This Land is Your Land
This Little Light of Mine
Yesterday
Zip-A-Dee-Doo-Dah

We need to add: Swinging on a Star for one.