The cost of milk in the 1960s was about $0.49 per gallon. In the 1970s, the cost of a gallon of milk rose to $1.15. In the 1980s, costs continued to rise to $2.16 per gallon.
Consumers in the 1990s could purchase a gallon of milk for $2.78. As of 2015, the price of a gallon of milk averages around $3.89.
California and Wisconsin provide most of the milk in the United Sates. Milk prices have historically been an indicator of how well the economy is performing. A more sluggish economy is bad for milk prices. Milk prices are expected to drop in the spring of 2015, according to International Business Times, after setting record price gains in 2014.