James Cook Ayer (5 May 1818 Groton, Connecticut – 3 July 1878 Winchendon, Massachusetts) was the wealthiest patent medicine businessman of his day. Dr. Ayer was also brother of wealthy industrialist Frederick Ayer.
At the age of 13, he moved to Lowell, Massachusetts, and resided there with his uncle. His education was obtained at the public schools, where at one time he was a classmate of Gen. Butler, and subsequently at the Westford Academy, after which he was apprenticed to James C. Robbins, a druggist in Lowell. While there he studied medicine, and later he graduated from the medical school of the University of Pennsylvania.
Ayer never practiced medicine, but devoted his principal attention to pharmaceutical chemistry and the compounding of medicines. His success in this line was very great, and soon led him to establish a factory in Lowell for the manufacture of his medicinal preparations, which became one of the largest of its kind in the world, and was magnificently equipped. He accumulated a fortune estimated at $20,000,000.
Much of his success was due to his advertising, and he published annually an almanac, 5,000,000 copies of which were gratuitously distributed each year. Editions in English, French, German, Portuguese, and Spanish, were regularly issued. In 1874 he accepted the Republican nomination for the United States Congress in the 7th Massachusetts District, but was defeated.
In addition to his patent medicine business, Dr. Ayer was involved in textile production in Lowell, Massachusetts with his brother. The town of Ayer, Massachusetts is named for him. He died in an asylum on July 3, 1878 and is interred at Lowell Cemetery. His son, Frederick Fanning Ayer, born 1851, became a lawyer and philanthropist, and was director or stockholder of many corporations.