James Wharton McLaughlin, physician, teacher, and editor, son of Cyrus Duncan and Sarah (Wharton) McLaughlin, was born near Springfield, Ohio, on September 7, 1840. After receiving his early education in the public schools of Ohio he began studying medicine with his uncle, Dr. Andrew C. McLaughlin. He attended the Cincinnati College of Medicine and Surgery in 1859–60. During the Civil War he served in the Confederate Army. Subsequently he set up a medical practice near Columbus, Texas. He received his M.D. degree from the University of Louisiana (now Tulane University) in 1867, and that same year he married Tabitha Bird Moore of Fayette County, Texas. They had six children. In 1870 the family moved to Austin, where McLaughlin practiced medicine until his appointment in 1897 to a chaired professorship in the medical department of the University of Texas at Galveston (see UNIVERSITY OF TEXAS MEDICAL BRANCH AT GALVESTON).
McLaughlin was an active member of the Texas State Medical Association (now the Texas Medical Association); he served on various committees and was elected president in 1894. His other professional affiliations included the American Medical Association, American Public Health Association, Southern Surgical and Gynecological Association, Austin Microscopic Society, and Travis County Medical Society. McLaughlin was a regent of the University of Texas (1907–09) and the president of the Texas Academy of Science in 1909. He was one of the founders of the Texas Sanitarian, an early journal devoted to public health, and he became its senior editor in 1894. After the publication changed its name to Texas Medical News in 1895, McLaughlin continued as the coeditor until 1898.
He published almost thirty articles, mostly on infectious diseases and immunology, and one monograph, Fermentation, Infection, and Immunity (1892). His publications on dengue fever, explaining the results of his experimental research, gained him a national reputation. He was among the first doctors in Texas to advocate the use of the microscope in clinical medicine. During the Texas dengue epidemic of 1885, which severely affected the population of Austin, McLaughlin made an early and noteworthy attempt to isolate the microorganism associated with the disease. Dengue fever was later shown to be a viral infection, however, and with the microscopes available in 1885 McLaughlin could not have seen the virus. During his tenure at the medical school in Galveston, he expanded the clinical laboratory and incorporated laboratory techniques into clinical teaching. He emphasized repeatedly that a physician is "morally, if not legally" obligated to employ the microscope in the diagnosis of diseases. In 1905 McLaughlin resigned from the medical department and returned to Austin. He was Scottish-English and a Democrat. He died of cancer on November 13, 1909. The James W. McLaughlin Fellowship Fund for the Investigation of Infection and Immunity, which supports various research projects and visiting professorships at the UT Medical Branch, was established by McLaughlin's son, Andrew Cyrus McLaughlin.