Did you know that if you buy yellow margarine in Missouri you're commiting a crime? A 19th century state law banned the sale of yellow margarine, though "it's been years since any violator was ordered to spread 'em."
Most of Missouri's restrictions on imitation butter date to 1895, and they were last amended in 1939. Although the state no longer enforces them, the penalties could still make dealers in contraband dairy product toast: up to a month in jail and a $100 fine for first-time offenders and six months in jail and a $500 fine for repeat offenders.
Enforcement of the law falls to the state Agriculture Department, and officials there didn't know when someone was last prosecuted under it. Case records from the late 19th and early 20th century show that Missouri courts upheld the constitutionality of the restrictions in several appeals.
Agriculture Department spokeswoman Misti Preston said it's likely that the Legislature restricted margarine and other imitation butter products to protect Missouri's dairy industry, which was a key business for the state in the early 20th century.
Link (yep, I got the the funny title from there) - via Bits & Pieces
"When I was in the service, military messes and chow halls could only serve real butter. Don’t know if that’s still the case."
Some time while I was in the navy (66-86) I heard they were required by law to serve only butter. So it was still in effect til mid 60's at least.
Thank you for your service Paul.
(There is some federal law from 1886 regarding margarine and butter but I couldn't find anything definite and gave up. Not even sure if that's the one.)