I thought so too until I did a quick search. Turns out that a series of events, including a strike at the Milwaukee plant, led to the phrase. Interesting article - Schlitz used to be THE beer after the Chicago fire. A side note - Pabst Blue Ribbon is mentioned in the article. PBR is the only beer that we could get in Vietnam (other then the local, ugh, stuff). That was in the south delta region of Vietnam where the 9th Infantry Division operated.