With its history rooted in the Middle Ages, the Doctor of Philosophy, or Ph.D., has developed over time to become the highest academic doctoral degree in the world. It acquired this distinction in the 1800s in continental Europe before spreading westward to the United States and Canada.

History
The doctoral degree originated in the ninth century schools of the Muslim world before spreading to European universities. Originally awarded in the professions of law, medicine and theology, the Doctor of Philosophy (Ph.D.) became the designation for doctoral degrees in disciplines outside of these fields. The first Ph.D. was awarded in Paris in 1150, but it was the early 1800s before the degree gained its contemporary status as the highest academic honor.

Identification
Friedrich Wilhelm University in Berlin, Germany, was the first university to award a Ph.D. for a course of study that today's doctoral students would recognize; that is, a sequence of coursework, followed by completion and successful defense of a dissertation of original research.

Geography
The Ph.D. spread to the United States in the 1800s. Prior to its development, Americans pursued doctoral study in European universities. According to the National Science Foundation, an estimated 10,000 Americans traveled to Europe for advanced university study. In 1900, the Ph.D. spread to Canada and in 1917 to Great Britain. In Great Britain, the Ph.D. displaced the existing D.Phil. and other doctorate degrees in some universities.

Important Firsts
In 1861, Yale University was the first American institution of higher education to award the degree, conferring it on three recipients: Arthur W. Wright, James M. Whiton and Eugene Schuyler. Wright received a Ph.D. in physics, while Whiton's degree was in classics. According to a Journal of Higher Education article, incomplete Yale records do not indicate the field Schuyler studied or the title of his dissertation.

The first Ph.D. awarded to an African-American was at Yale University in 1876. A year later, the first woman received a Ph.D. in the United States.

Features
The National Science Foundation reported that American universities awarded more than 1.3 million doctoral degrees from 1920 to 1999. Science and engineering fields accounted for 62 percent of these degrees, while other fields comprised the remaining 38 percent. Men accounted for 73 percent of the recipients, but the proportion of Ph.Ds earned by women has risen, from 15 percent in the 1920s to 41 percent by the late 1990s.