William J. Beal was born on March 11, 1833 in Adrian, Michigan. In 1859, he graduated from the University of Michigan with a B.A. degree in classical studies. After two years of teaching material science at The Friend's Academy in Union Springs, New York, Beal enrolled at Harvard. While there, he studied under famous botanists, Asa Gray, Louis Agassiz, and Jeffries Wyman, and eventually graduated with his B.S. degree.

In 1871, Beal began his long association with Michigan Agricultural College (now Michigan State University) as a professor of botany and horticulture. A pioneer in teaching "The New Botany" as outlined in his 1880 address, Beal placed great emphasis on independent learning through observation. Several of his students went on to become prominent scientists including C. S. Crandall, professor of pomology at Illinois; C. C. Georgeson who developed wheat and strawberries capable of withstanding Alaska's climate; and Liberty Hyde Bailey who became a world authority on palm species. Perhaps Beal's greatest achievement was his experiments in cross-fertilization of corn which led directly to the development of hybrid corn. His most enduring act was the establishment of the oldest continuously operated garden in the nation in 1873: Beal Botanical Garden at Michigan Agricultural College. This garden is recognized as one of the best in the country serving as both an outdoor teaching lab and a focal point for naturalists. In 1910, Beal retired after forty years of service to write a history of M.A.C. He spent his remaining years in Amherst, Massachusetts until his death in 1924.