This tradition was started in 1937 buy a milk company Exec. The Exec had seen a picture of Louis Meyer after he had won the Indy 500 in 1936 drinking Butter Milk in victory lane, but mistakenly thought that Louis Meyer was drinking regular milk. The tradition went fron 1937 thru 1941, then again in 1946, and then every year from 1956 until today.
For more info on Indianapolis 500 traditions go to http://www.indy500.com/traditions/



