The article, which appeared in the May 12, 1952, issue of Life Magazine, profiles Walt Kelly and his popular comic strip, Pogo. Running from page 12 to 14 of that issue, it includes a stunning one-and-one-half page drawing of the swamp, populated with many of the swamp denizens, all in dialogue!
Here's a sample, roughly half the page, scanned from the photocopy. Click for detail!
Here's the cover of the issue, readily available for purchase online. Comic strip fans will also be interested in the cover from March 31 of the same year, showing Li'l Abner being married to Daisy Mae.
While trying to find online images from the internet, I found the following at the Life archives on Google. It seems Walt Kelly was visiting Harvard University to stump for presidential candidate Pogo Possum at New Lecture Hall.
The historic "I Go Pogo" candidacy was created not by Walt Kelly, but by the editors of the Harvard Crimson newspaper. (This might be open to interpretation. It is possible that Kelly started the promotion to increase newspaper and book sales.) The newspaper endorsed not Adlai Stevenson or Dwight D. Eisenhower, but Pogo Possum.
The idea snowballed, and soon Kelly was invited to speak at the University. His arrival was late, and a waiting crowd of 200 people swelled to 1600, causing traffic jams. Eventually, Cambridge police, simmering under town-gown prejudices, instigated crowd control, beating participants and arresting 28 students. The "Pogo Riot" thus entered the history books.