1 mayo 1947 año - State of Michigan
requires pasteurization
of milk
Descripción:
 "Michigan became the first state to require pasteurization of milk."
Source: 
https://www.ncleg.gov/DocumentSites/Committees/HSCAR/Meetings/2011-2012/4%20-%20March%207/2012-0307%20B.Riley-%20NCGA%20Research%20-%20Fed%20and%20State%20Regs%20of%20Raw%20Milk%20Presentation.pdf 
Añadido al timeline:
fecha:
1 mayo 1947 año
Ahora mismo
 ~ 78 years ago