“All Right Now” - Free
“In-A-Gadda-Da-Vida” - Iron Butterfly
“White Bird” - It’s A Beautiful Day
Yeah. That’s one I can actually see people go violent over if the band doesn’t play it.
You remember “Carrie”, don’t you? That one really brought out all the Bic lighters.
“Thunderbird” by Quiet Riot
Both are good calls for this OP, but (and only because people always forget them when talking about one-hit wonders);
Focus had a #4 song in UK (#89 in US) with Sylvia, and Radar Love only reached #13 in US. Twilight Zone hit #1.
How 'bout
Who’s Behind The Door? by Zebra?
Holy War by Jon Butcher Axis?
Jim Dandy by Black Oak Arkansas?
Keep On Smiling by Wet Willie?
Jackie Blue by Ozark Mountain Daredevils?
Brother Louie by Stories?
Don’t Call Us, We’ll Call You or Green-Eyed Lady by Sugarloaf?
Vehicle by Ides Of March?
One Fine Morning by Lighthouse?
Hold Your Head Up by Argent?
Rock On by David Essex?
Fresh Air by Quicksilver Messenger Service?
World Anthem by Frank Marino And Mahogany Rush 
And the anthemest anthem of all
Born To Be Wild by Steppenwolf.
God I love that Head East song. As well as many many of second-echelon 70s bands.
Wishbone Ash comes to mind when pondering the anthemic, second-echelon styley.
Blowin’ Free. http://www.youtube.com/watch?v=EeY9IRnVmk8
Phoenix. http://www.youtube.com/watch?v=MVUx4zxd7VA
Warrior. http://www.youtube.com/watch?v=hg6zqejXvqI
How 'bout Uriah Heep?
The Wizard. http://www.youtube.com/watch?v=u0iuaxvkXv4
Easy Livin’. http://www.youtube.com/watch?v=m4o--q6xuvs
Not long enough to be truly anthemic, you say? Then how bout
July Morning. http://www.youtube.com/watch?v=D_H3IR6XBRI
Hmm. Who else?
Oh yeah! Blackfoot! Couldn’t be more second-echelon or anthemic.
Highway Song. http://www.youtube.com/watch?v=8MYM9OU6cuE
Ditto for Mountain.
Nantucket Sleighride. http://www.youtube.com/watch?v=1-XxLQkSGWo
I could do this all day.
Not second-echelon per se, but pre-metal stardom. Early Judas Priest, with Rob Halford looking a bit like Neil from The Young Ones.
Dreamer Deceiver. http://www.youtube.com/watch?v=LXBnAhMDFdI
Gotta have All The Young Dudes if yer talkin anthemic.
How bout Robin Trower?
Bridge of Sighs. http://www.youtube.com/watch?v=x0d1HilfLxA
The great great Maggie Bell and Stone the Crows. There is a bunch of live stuff on YouTube that sucks sound-quality wise but here’s a great track from Teenage Licks, which by the way is one of the best album covers ever.
Faces. http://www.youtube.com/watch?v=IPX9dK4c9Io
I gotta go to school dammit.
Oh man, I thought I had come to terms with my super-thread-killing abilities, but this… this just hurts. Not one response to all the second-echelon anthemic grooviness I worked so hard to dig up? Oh man… ouch. I am the thread killer extraordinare. He is me.
No way, man…I’m still digging it…
These two are currently touring together:
Rick Derringer - “Rock And Roll, Hoochie Koo”
and
Pat Travers - “Boom Boom (Out Go The Lights)”
I’m still trying to wrap my head around someone who has to “go to school dammit” having heard of Stone The Crows (and with a song I’d forgotten, no less). 
Next you’ll be telling me you know Captain Beyond!!
Nope, but thanks for the link. I’m 46, btw. Never too late to better oneself, don’t cha know.
Been pondering the OP. Two ways to go with it. The songs listed are great big long guitar jam things. Anthems, on the other hand, are great big hook-laden soul-stirring things, can be long or short. Sometimes, of course, the two conflate.
For the first definition, can’t beat the Marshall Tucker Band. Love the bass solo in this one, especially on the album. Just love this song. Volunteer Jam must have been a blast.
24 Hours at a Time. http://www.youtube.com/watch?v=X0L5LD7GZxc
How could I forget the Nuge? This kicks fucking ass. Anthemic and guitar jammy all at once.
Great White Buffalo. http://www.youtube.com/watch?v=O3J-XYnZHfU
How bout Sniffin’ the Tears? Loved loved LOVED this song when it came out.
Driver’s Seat. http://www.youtube.com/watch?v=JFwcmU6Ql0A&NR=1
Here’s Sweet.
Love Is Like Oxygen. http://www.youtube.com/watch?v=kRVwcPTnug8&NR=1
There was a singles version and an album version of this. Always liked it when they played the long one.
And Flash and the Pan. Crazy stuff when it came out.
Walking in the Rain. http://www.youtube.com/watch?v=cJFB0roVxaM&feature=related
I’ll keep thinkin’ on this. Thanks all!
how about …
Switching to glide/the beat goes on by The kings
Ahh leah! by Donnie Iris
Lastly, two of my favorite tunes from one of my favorite bands, Roxy Music. Their first 5 albums are true psychedelic/hard rock masterpieces. After that they pretty much blew.
Mother of Pearl. Such a gorgeous, nay, anthemic number.
In Every Dream Home a Heartache. Perhaps the most tender paean to a blow up love doll ever written. Ferry looks and sounds like a vampire on heroin here. Move over Twilight! Not sure exactly what Eno looks like.
Love Ah Leah, Roland! Great great song.
GODDAMN Eno and Manzanera giz out to the nth degree on that last one. Made me remember 801. Good good stuff.
Tomorrow Never Knows. http://www.youtube.com/watch?v=ug-uMnKjUW8
I’ll stop now. I get overexcited.