In 1830, John K. Smith opened a drugstore in Philadelphia, and his younger brother, George, joined him in 1841 to form John K Smith & Co. In 1865, Mahlon Kline joined Smith and Shoemaker, as John K Smith and Co had become in the meantime, as a bookkeeper. In 1875, he took on additional responsibilities as a salesman and added many new and large accounts, as a reward the company, Mahlon K Smith and Company, was renamed into Smith, Kline and Company.
In 1891, Smith, Kline and Company acquired French, Richards and Company, which provided the company with a greater portfolio of consumer brands. In 1929 Smith, Kline and French Company was renamed into Smith Kline and French Laboratories and the company put more focus on research in order to sustain its business. In 1968, the company acquired Recherche et Industrie Thérapeutiques in Belgium and changed its name in SmithKline-RIT.
SmithKline acquired Allergan in 1982, an eye and skincare business, and merged with Beckman Instruments, Inc., a company specialising in diagnostics and measurement instruments and supplies. After the merger the company was renamed SmithKline Beckman.