The first Playboy Club opened in Chicago.
Dr. Bernard Fantus and his team opened the very first 'blood bank' in Cook County Hospital, Chicago, US.
Coopers Inc. started selling the world's first men's briefs in Chicago.
The Saint Valentine's Day Massacre took place in Chicago.
The first Sears retail store opened in Chicago.
The first telephone call was made between New York and Chicago.
The sweeping machine (vacuum cleaner) was patented in Chicago, US, by Ives W. McGaffey.
