smaller retailers and traditional 'Mom and Pop' stores couldn't help but start dieing off due to stores such as Walmart, Kmart, Target and etc. Mom and Pop stores can't compete with the prices of the larger stores. My best guess would be somewhere in the 1980's
Target Corporation's main retailing subsidiary, Target Stores,
is a United States discount retail chain consisting of 1,591 stores
(as of October 2007). It has units in all states except for Hawaii
and Vermont, operating under the mastheads of Target, Target
Greatland, and SuperTarget.