Antibiotic development for the masses began in the 1920s, and by the 1950s, studies began revealing concerns about the development of antibiotic resistance. However, resistance genes in bacteria have been around for millions of years, long before antibiotics were widely used. In a poultry flock, a “resistome” exists for both the flock as a whole and for individual birds. If resistance genes encourage multiple resistance for different antibiotics, treatments may not be as effective for the flock. Learn how the story of antibiotic resistance throughout history will help inform how we manage this issue now and into the future.