Crawford, John (1746–1813), doctor, medical publisher and public benefactor, was born 3 May 1746 at Ballytromery near Crumlin, Co. Antrim, second son among six children of Thomas Crawford (d. 1782), presbyterian minister and farmer, and Anne Crawford (née Mackay). His elder brother was William Crawford (qv) (d. 1800), a prominent presbyterian minister, Adair Crawford (qv), a doctor and chemist, and Alexander Crawford (qv) a doctor and United Irishman, were younger brothers, and they had two sisters. Thomas Crawford senior was himself son and grandson of presbyterian divines noted in their day; he was minister in Crumlin from 1724 until his death, and farmed the congregational farm. Anne Crawford was the aunt of the novelist Elizabeth Hamilton (qv) (d. 1816) and her brother Charles (qv) (d. 1792), an orientalist.
John Crawford was educated locally, perhaps by his father; he is said to have attended lectures at TCD from about the age of seventeen, but an assertion that he graduated there is unconfirmed. He was probably apprenticed to a Dublin doctor, and between 1772 and 1774 he was surgeon on board the East India Company ship Marquis of Rockingham on voyages to Bombay and Bengal; he seems also to have visited China and St Helena. In 1772 he published an account of a liver disease fatal in hot climates, which may have been beriberi. He possibly visited Ireland around 1778; around that time he married Mary, daughter of John O'Donnell and Barbara O'Donnell (née Anderson) of Trough, on the border of Co. Clare and Co. Limerick. It is possible that he met her through knowing her brothers in the East India Company: John O'Donnell (d. p. 1805?) had an adventurous career in the east before becoming a very prominent merchant in Baltimore, Maryland, and Henry Anderson O'Donnell (b. 1758) married a Persian princess.
Crawford and his wife went to Barbados, on his appointment as surgeon to the hospital there. When a hurricane in 1780 devastated the island, Crawford could have made a great deal of money from his surviving supplies of food and medicine, but instead gave them away to those in need. His health broke down due to overwork and exposure, and in 1782 he and his wife and two small children travelled to England on furlough, but his wife died on the voyage. Crawford was forced to leave his children behind in England when he returned to Barbados in 1786. In 1790 he became surgeon-major in Demerara, then a Dutch colony, and in 1794, on a visit to Europe, he took his MD in the Dutch university of Leiden; the university of St Andrews had granted him the degree of MD in 1791.
John O'Donnell, Crawford's brother-in-law, suggested that he and his children should settle in Baltimore, Maryland, and in 1796 he moved there. He found himself among ‘more of the branches of the families amidst of which I was born than I have ever seen since I left my native country’ (quoted in Wilson (1942)), and was made most welcome. He was friendly with the famous doctor Benjamin Rush, and established a good practice. He enthusiastically studied the natural history of his new environment, as he had done in the tropics; he had a wide knowledge of botany and entomology. Even before 1794, when he discussed his ideas with the medical faculty in Leiden, he had come to the conclusion that insects at various stages of their life-cycles could be vectors of diseases in humans. This had been suggested in outline by earlier authors, but a theory of the role of ‘animalculae’ in the spread of disease had never found any backing, as it was contrary to the then generally accepted doctrine that fevers and agues resulted from exposure to miasma (the very name of malaria still expresses this long-held idea) or from simple contagion. Crawford was first to suggest that insects were involved in the spread of yellow fever. Other medical men poured scorn on his novel ideas, and his practice and reputation suffered.
In 1804 Crawford started publishing a weekly magazine, the Companion and Weekly Miscellany, using the pseudonym of Edward Easy, and in 1806 transferred the editorship to his daughter Eliza, who thus became the second woman editor in the United States. In this weekly, retitled The Observer and Repertory . . ., he published during 1806–7 his ‘Theory and application to the treatment of disease’. Some notice was taken of his ideas, but he found no adherents. Even in 1811, when he planned a course of lectures on the cause and treatment of diseases, he was not hopeful of convincing his opponents. He wrote to Benjamin Rush that ‘my situation can not be made worse by it . . . My contemporaries may not thank me for the attempt; I know they will not: my great aim is to do good, and I leave the issue to him from whom I have received what I have’ (quoted in Wilson), and in the published version of the only lecture that is known to have been delivered he pledged that as long as ‘life and health remain, I shall devote myself strictly to the performance of my duty’. A number of palliative and curative measures for use in epidemic diseases, involving inter alia rigorous hygiene of the sickroom, were suggested by Crawford on the basis of his theory; some are now established as routine medical practice, though his opposition to any idea of contagion as a means of infection vitiates a few of his recommendations.
As well as his importance as a pioneer of a theory of insect-borne disease, Crawford is recognised as one of the two doctors who first introduced vaccination against smallpox into America. In the summer of 1800, at the same time as Benjamin Waterhouse was also experimenting with cowpox, Crawford received vaccine from London, and apparently successfully vaccinated at least one person. He published nothing on his vaccination work, but rejoiced in 1807 that smallpox had been rendered nearly harmless by the new technique. Crawford was involved with other projects to benefit his fellow citizens in Baltimore: he was one of the founders of Baltimore Library (1798) and of a Society for the Promotion of Useful Knowledge in the city (1800). He helped to establish a dispensary in Baltimore (1801) and a state penitentiary, and suggested improvements in training military and naval medical men. He was consulting physician to the Baltimore hospital, an examiner in the Baltimore medical faculty, and briefly (1812) held a lectureship in natural history in Baltimore Medical College. He was prominent in the city's Hibernian Society, and was grand master of the Masonic order in Maryland in every year but one from 1801 until his death, which took place on 9 May 1813. He was buried with Masonic honours in Westminster presbyterian graveyard in Baltimore; James McHenry (qv) (1753–1816), also a doctor, a Mason, and from Co. Antrim, is buried in the same place. Crawford's valuable and important library was bought by the University of Maryland at auction in 1813; the first major book purchase of that institution, it forms the nucleus of what is now known as the Health Sciences and Human Services Library.
His daughter Eliza survived him; she had led an adventurous life, having travelled to France as companion to Elizabeth Patterson (1785–1879), first wife of Jérôme Bonaparte (1784–1860). She married first Henry Anderson, probably a relative, then left him and married secondly Maximilian Godefroy, a noted architect. Crawford lived with them from their marriage (1799) until his death. He and his daughter are described by Elizabeth McCalmont (née Barklie) of Larne, Co. Antrim, in memoirs published by F. J. Bigger (qv). Crawford's son seems to have trained in medicine in London, but may have died of consumption before his father.