'69 was tremendously strong. Check it...
Led Zeppelin - Led Zeppelin
Bayou Country – Creedence Clearwater Revival
Dr. Byrds & Mr. Hyde – The Byrds
Happy Trails – Quicksilver Messenger Service
Spooky Two – Spooky Tooth
The Velvet Underground – The Velvet Underground
Nashville Skyline – Bob Dylan
With a Little Help from My Friends – Joe Cocker
On the Threshold of a Dream – The Moody Blues
Chicago Transit Authority – Chicago
Stand! – Sly & the Family Stone
Everybody Knows This Is Nowhere – Neil Young and Crazy Horse
Tommy – The Who
Crosby, Stills & Nash – Crosby, Stills & Nash
Clouds – Joni Mitchell
Last Exit – Traffic
Trout Mask Replica – Captain Beefheart
The Soft Parade – The Doors
Blind Faith – Blind Faith
Green River – Creedence Clearwater Revival
Santana – Santana
Ssssh – Ten Years After
Stand Up – Jethro Tull
I Got Dem Ol' Kozmic Blues Again Mama! – Janis Joplin
The Band – The Band
Abbey Road – The Beatles
Hot Rats – Frank Zappa
In the Court of the Crimson King – King Crimson
Led Zeppelin II – Led Zeppelin
Willy and the Poor Boys – Creedence Clearwater Revival
Volunteers – Jefferson Airplane
Let It Bleed – The Rolling Stones
Liege & Lief – Fairport Convention
Harry – Harry Nilsson
It's a Beautiful Day – It's a Beautiful Day
Just a small sampling. There was a whole lot more happening. Seems like a peak period to me.