In 1895, Johnson developed a side business called The American Ferment Company to create a digestive aid.

The firm moved to Evansville, Indiana, in 1915, in the wake of World War I, as part of an effort to have easier access to the raw agricultural ingredients that were needed for its products, which required Johnson to build a series of new plants and factories to replace the ones he had left behind in New Jersey.

[6] A plan offered in November 2009 would allow shareholders of Bristol-Myers to exchange one dollar of stock in that company for $1.11 worth of shares in Mead Johnson for the 133.5 million shares in the firm, which would value the company at $7.7 billion based on the stock's then current closing price.

CEO James M. Cornelius of Bristol-Myers said that "With a successful execution of this split-off, we fully consider ourselves a BioPharma company".

[8][9] On February 10, 2017, Reckitt Benckiser Group announced it had agreed to buy Mead Johnson Nutrition Co. for $16.6 billion.

On June 15, 2017, the merger was completed and Mead Johnson became the Infant Formula and Child Nutrition (IFCN) Division of RB.