Educator and Administrator, was born in Lexington, Ky., the second son and second child of the Rev. William Dinwiddie, a Presbyterian minister, and Emily Albertine Bledsoe, daughter of Albert Taylor Bledsoe, assistant secretary of war for the Confederacy. Shortly after his birth, the family returned to Greenwood, Albemarle County, Va. Here he passed his boyhood, taking active part in the sports of the Blue-Ridge section, especially hunting and fishing. He prepared for college at Potomac Academy, Alexandria, Va., and entered the University of Virginia in 1886. His plan to study medicine had to be abandoned for financial reasons. Neither his youth (he entered a year too young to receive free tuition) nor the outside work required for his expenses interfered with his studies, and he graduated in three years, in 1889. By instructing at the University School, Charlottesville, 1889-91, he financed his graduate study, taking the degrees of A.M. in 1890 and Ph.D. in 1892. His doctoral dissertation was a study of indirect discourse in Thucydides. From 1891 to 1893 he was principal of Greenwood Academy in Virginia, a private school owned by the family. He was first assistant at the University School, Richmond, 1895-96, and from 1896 to 1906 he was professor of mathematics at Southwestern Presbyterian University, Clarksville, Tennessee. During 1902-03 he studied higheer mathematics at the University of Gottingen and while there enjoyed walking trips in Germany and Switzerland.

In 1906 he went to Tulane University, New Orleans, La., as assistant professor of applied mathematics and astronomy, advancing to associate professor in 1908 and to professor in 1910. For some years he supplemented his salary by writing book reviews for the Picayune. With his appointment as dean of the college of arts and sciences and director of the summer session in 1910 his administrative career began. Tulane University had for several years lacked vigorous leadership. The endowment was inadaquate, the faculty morale was low, and scholarly standards were threatened. The First World War brought Dinwiddie his first great opportunity. As director of war training, 1917-18, he moved Camp Martin the the Tulane campus and organized training courses in several mechanical branches. On October 1, 1918, he became president of Tulane. A carefully organized endowment drive in 1920, succeeded. The faculty was strengthened, salaries were improved, new departments, such as the Middle American Research Institute and the School of Social Work, were organized, and several buildings were erected. A retirement plan was begun, and group insurance was instituted. During his seventeen-year presidency the endowment grew from three to ten million dollars, the student body doubled, and the university became nationally known.

As a member of the Louisiana State Board of Education from 1922 until his death, Dinwiddie exercised a salutary influence. In the Association of Colleges and Secondary Schools of the Southern States he was an important figure and was its president in 1922. He was made a trustee of the Carnegie Foundation for the Advancement of Teaching in 1923. It was his nature to be conservative; he preferred to support established educational procedures rather than to encourage experiment.s He was thorough and practical, unhurried in manner, deliberate and clear in speech, and conveyed an impression of quiet power and integrity. An almost extreme simplicity of taste accompanied a warm kindliness. His rapid-fire wit was reserved for his intimates. Fishing was his favorite relaxation, and he strongly supported college athletics. He died after a long illness from heart disease. He was married, on July 22, 1897, to Caroline Arthur Summey, daughter of the Rev. George Summey, a Presbyterian minister, of Clarksville, Tennessee. They had six children: Emily, Elizabeth Worth, Albert, George, Mary, and William.

(Who's Who in America, 1934-35; Times-Picayune (New Orleans), November 22, 1935; the New Orleans States, March 31, 1929; files in the president's office, Tulane University; information as to certain facts from members of Dinwiddie's family.)